feat: Add new migration for DVO Cook'n

[keyofdminer]

What this PR does / why we need it:

(REQUIRED)

This pull request adds the functionality of being able to import cookbooks from DVO Cook'n X3 (it might also work with newer or older version, but I am unable to test that).

File changes:

• Updated docs with Cook'n as migration option
• Updated frontend files with Cook'n options and text matching existing migrators
• Added Cook'n to SupportedMigrations
• Added actual cook'n migration code
• Add test case (MigrationTestData)

Notes:
This directly supports ingredient amounts. To do this I have imported all ingredients and foods used from the Cook'n library (duplicates are hopefully mitigated by using the fuzzy matching in DataMatcher).

Special notes for your reviewer:

(fill-in or delete this section)

Focus should primarily be on mealie/services/migrations/cookn.py. As 95% of the changes are in that file. Functionally the code should be pretty good, but formatting, code consistency, and documentation might need some touch ups.

P.S. This is my first time working with strict typing, vue, and docker. So apologies up front if I am missing anything.

Testing

(fill-in or delete this section)

I have tested it with all my recipes from Cook'n (about 750). Doing a spot check everything seems to be in order. The included test only has 3 recipes, but I can update it with more if needed.

I also ran py:check with the following pytest results:

FAILED tests/integration_tests/admin_tests/test_admin_group_actions.py::test_admin_update_group - sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) UNIQUE constraint failed: groups.slug
1 failed, 1209 passed, 26 skipped, 161 warnings in 932.06s (0:15:32)

[michael-genson]

Hey there!

Haven't had the chance to give this a proper lookover yet, but FYI you only need to update en-US.json for new lang strings. The other languages will be added automatically through Crowdin

[keyofdminer]

Good to know. I am not very familiar with i18n and just used the VSCode extension to generate everything. I can remove the other languages if that would be better.

[michael-genson]

Yes please, we'll need them reverted for the PR (otherwise Crowdin will overwrite them)