Refactor: Add IdsMixin to replace extract_ids() utility method

[glensc]

Carry moogar0880#186

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Extracting the "ids" on each response is tedious, and such duplication results users being confused:

• UserList.add_items not working moogar0880/PyTrakt#78 (comment)
• AttributeError: 'Movie' object has no attribute 'trakt' moogar0880/PyTrakt#158 (comment)

Also, the existing extraction is inconsistent (Not applied for TVShow and Movie in this example):

• https://github.com/moogar0880/PyTrakt/blob/8a6d4f168a858447014fb4c2c0efceb47b30ebb7/trakt/sync.py#L331-L342

This will make the ids extraction automatic, and prevent updating the attributes directly.

Additionally it came out that properties like tmdb_id, imdb_id, trakt_id are unused. they are initialized as None in the constructor but never any other value. these are commented with @deprecated and are to be removed in 4.x.

• Person
• Movie
• Calendar
• SearchResult
• TVShow
• TVEpisode
• TVSeason
• UserList

TODO:

• rebase after [python-pytrakt] Cleanup: Drop classes extending from object moogar0880/PyTrakt#187

[glensc]

LGTM. Tested:

• make tests
• plextraktsync@1274 (Update pytrakt to 3.4.15 Taxel/PlexTraktSync#1274)