[Trakt] Support locked user accounts

[UweTrottmann]

Starting today, we’re sending a 423 error code for locked user accounts. Apps should instruct the user to contact support (https://support.trakt.tv) so we can fix their account.

API docs:
https://trakt.docs.apiary.io/#introduction/locked-user-account

Discuss:
trakt/api-help#228

https://twitter.com/traktapi/status/1325889876768612352

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