refactor: integrate rate limiting and caching into service sessions

[iPromKnight]

• Introduced create_service_session to handle session creation with optional rate limiting and caching.
• Replaced direct requests with session-based requests across multiple modules.
• Added TraktAPI, OverseerrAPI, ListrrAPI, and PlexAPI classes to encapsulate API interactions.
• Updated scrapers and content modules to use new API classes and session management.
• Implemented unit tests for request handling and session creation.
• Improved error handling and logging for API requests.
• Removed redundant rate limiter and request handling code.

I've not enabled any caching atm - but we have the option for ANY session to have an independant sqlite cache now fully controllable with cache age etc

The service session constructor takes in parms to enable rate-limiting, caching or both ratelimiting and caching.

I've separated some API concerns from services, into separate classes, and updated all modules with the refactors

Seems to be working for me locally

Also - i've added rate limiting back to real debrid because its been updated to use the new session system.

replaced resquests class also has all unit tests added.

[iPromKnight]

The caching (if we enable caching) stores them in sqlite databases for each of the instances, so they aren't in memory

The buckets for rate limit tokens are stored in memory, but we were doing that before :)