fix Fallenbagel#227

…lenbagel#748)

* fix(logging): handle media server connection refused error/toast

Properly log as connection refused if the jellyfin/emby server is unreachable. Previously it used to
throw a credentials error which lead to a lot of confusion

* refactor(i8n): extract translation keys

* refactor(auth): error message for a more consistent format

* refactor(auth/errors): use custom error types and error codes instead of abusing error messages

* refactor(i8n): replace connection refused translation key with invalidurl

* fix(error): combine auth and api error class into a single one called network error

* fix(error): use the new network error and network error codes in auth/api

* refactor(error): rename NetworkError to ApiError