* refactor(jellyfinapi): use the external api class for jellyfin api requests
refactors jellyfin api requests to be handled by the external api
to be consistent with how other external api requests are made
related #728, related #387
* style: prettier formatted
* refactor(jellyfinapi): rename device in auth header as jellyseerr
* refactor(error): rename api error code generic to unknown
* refactor(errorcodes): consistent casing of error code enums