Add URLs to offers

[booxter]

No description provided.

[booxter]

Probably need to add an association proxy that would map to the new field, to Film db model: https://docs.sqlalchemy.org/en/20/orm/extensions/associationproxy.html The init for the Film class will receive offers that contain both the name and the URL and will initialize the corresponding relationship table record accordingly.

[booxter]

offers are now objects with url and name; this should be integrated into UI now. @nia-ja