Upstream fixes

* abstract out the form buttons (Add/Cancel/...)
* use `accordion.tree`
* Better targeting of tables in Control Explorer (now it is perfect, `table_in_object`)
* updated flash message, it did not read all success messages
* `select` in `pytest_selenium` did not move on the elements therefore caused errors. Fixed.

TO TEST
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`-k 'test_basic or test_actions or test_email or test_workers or test_providers or test_access_control'`
*if something fails and it is not a UI bug, then it should be ok*