Language imports consistently on re-imports of books

[qotkdrn]

Closes #10141 Internet Archive imports often missing language

Fix

Fixes language import issue by ensuring that language is correctly added to existing editions during import

Technical

Previously, the issue was that when importing an edition, the language field was not being correctly added to existing editions if it was missing, even if the import record contained a language.

To address this I added a helper function format_languages() to openlibrary/openlibrary/catalog/add_book/init.py,
to format the languages field, called by update_edition_with_rec_data() and build_query() in openlibrary/openlibrary/catalog/add_book/load_book.py, along with changes to both functions.

Testing

Tested this issue locally and reproduced the bug by running the following commands (generate command and import book).

$ curl -c cookies.txt -X POST "http://localhost:8080/account/login" -d "username=[email protected]&password=admin123"
$ curl -L -v -X POST "http://localhost:8080/api/import/ia"
-b ./cookies.txt
-d "identifier=isbn_9781849353946&require_marc=false&force_import=true"

The book should now appear under http://localhost:8080/books/OL5M/

However, if we delete the language field and reimport the book, the language fields remains missing.
http://localhost:8080/books/OL5M.yml?m=edit

After the changes, languages should now be correctly added.

Stakeholders

@scottbarnes