Created test for the Product Preparation model

refs #16581
Added product preparation model to models.py

refs #16581
Create Preparation model unit tests

Test if all fields are of proper type, and that only the expected fields
exist.
Make preparation model tests actually work
Rewrite preparation model tests based on Vendor model tests

Move into tests folder and use a dictionary to track test
Change unicode test string to ascii
Create Preparation model
Created test for the Product Preparation model

refs #16581
Added product preparation model to models.py

refs #16581
Rebase off of products model branch and add to prep/prod tests
Merge branch 'feature/16581' of https://github.com/osu-cass/whats-fresh-api into feature/16581

Conflicts:
	project_fish/whats_fresh/models.py
	project_fish/whats_fresh/tests/__init__.py
	project_fish/whats_fresh/tests/test_preparation_model.py
Created test for the Product Preparation model

refs #16581
Attempting to fix merge errors.
Create Preparation model unit tests

Test if all fields are of proper type, and that only the expected fields
exist.
Make preparation model tests actually work
Rewrite preparation model tests based on Vendor model tests

Move into tests folder and use a dictionary to track test
Created test for the Product Preparation model

refs #16581
Added product preparation model to models.py

refs #16581
Rebase off of products model branch and add to prep/prod tests
Merge branch 'feature/16581' of github.com:osu-cass/whats-fresh-api into feature/16581

Conflicts:
	whats_fresh/whats_fresh_api/models.py