Update flaubert with TF decorator
Author: Tegzes
Pull request: yes

Unpacks TF model inputs through a decorator, improving code clarity for the FlauBERT model. Linked to issue #16051

@gante 

Comments:
Report for the pytest run:

```
RUN_SLOW=1 pytest -vv tests/flaubert/test_modeling_tf_flaubert.py

========================================================================================= test session starts =========================================================================================
platform linux -- Python 3.7.11, pytest-7.1.1, pluggy-1.0.0 -- /home/tegzes/anaconda3/envs/transf/bin/python
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('/home/tegzes/Desktop/transformers/.hypothesis/examples')
rootdir: /home/tegzes/Desktop/transformers, configfile: setup.cfg
plugins: dash-2.3.0, xdist-2.5.0, timeout-2.1.0, hypothesis-6.39.4, forked-1.4.0
collected 36 items                                                                                                                                                                                    

tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_attention_outputs <- tests/test_modeling_tf_common.py PASSED                                                             [  2%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_compile_tf_model <- tests/test_modeling_tf_common.py PASSED                                                              [  5%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_config PASSED                                                                                                            [  8%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_determinism <- tests/test_modeling_tf_common.py PASSED                                                                   [ 11%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_flaubert_lm_head PASSED                                                                                                  [ 13%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_flaubert_model PASSED                                                                                                    [ 16%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_flaubert_qa PASSED                                                                                                       [ 19%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_flaubert_sequence_classif PASSED                                                                                         [ 22%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_for_multiple_choice PASSED                                                                                               [ 25%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_for_token_classification PASSED                                                                                          [ 27%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_forward_signature <- tests/test_modeling_tf_common.py PASSED                                                             [ 30%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_generate_with_headmasking <- tests/test_modeling_tf_common.py PASSED                                                     [ 33%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_headmasking <- tests/test_modeling_tf_common.py PASSED                                                                   [ 36%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_hidden_states_output <- tests/test_modeling_tf_common.py PASSED                                                          [ 38%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_initialization <- tests/test_modeling_tf_common.py PASSED                                                                [ 41%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_inputs_embeds <- tests/test_modeling_tf_common.py PASSED                                                                 [ 44%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_keras_save_load <- tests/test_modeling_tf_common.py PASSED                                                               [ 47%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_keyword_and_dict_args <- tests/test_modeling_tf_common.py PASSED                                                         [ 50%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_lm_head_model_beam_search_generate_dict_outputs <- tests/test_modeling_tf_common.py PASSED                               [ 52%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_lm_head_model_no_beam_search_generate_dict_outputs <- tests/test_modeling_tf_common.py PASSED                            [ 55%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_lm_head_model_random_beam_search_generate <- tests/test_modeling_tf_common.py PASSED                                     [ 58%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_lm_head_model_random_no_beam_search_generate <- tests/test_modeling_tf_common.py PASSED                                  [ 61%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_load_with_mismatched_shapes <- tests/test_modeling_tf_common.py PASSED                                                   [ 63%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_loss_computation <- tests/test_modeling_tf_common.py PASSED                                                              [ 66%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_model_common_attributes <- tests/test_modeling_tf_common.py PASSED                                                       [ 69%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_model_from_pretrained PASSED                                                                                             [ 72%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_model_main_input_name <- tests/test_modeling_tf_common.py PASSED                                                         [ 75%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_model_outputs_equivalence <- tests/test_modeling_tf_common.py PASSED                                                     [ 77%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_numpy_arrays_inputs <- tests/test_modeling_tf_common.py PASSED                                                           [ 80%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_onnx_compliancy <- tests/test_modeling_tf_common.py PASSED                                                               [ 83%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_onnx_runtime_optimize <- tests/test_modeling_tf_common.py PASSED                                                         [ 86%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_pt_tf_model_equivalence <- tests/test_modeling_tf_common.py SKIPPED (test is PT+TF test)                                 [ 88%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_resize_token_embeddings <- tests/test_modeling_tf_common.py PASSED                                                       [ 91%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_save_load <- tests/test_modeling_tf_common.py PASSED                                                                     [ 94%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelTest::test_save_load_config <- tests/test_modeling_tf_common.py PASSED                                                              [ 97%]
tests/flaubert/test_modeling_tf_flaubert.py::TFFlaubertModelIntegrationTest::test_output_embeds_base_model PASSED                                                                               [100%]
```

_The documentation is not available anymore as the PR was closed or merged._