Refactor: Optimize resolve_guid to check only once positive providers

[glensc]

The refactor checks provider only once for providers that exist, possible micro performance boost. For unmatched more checks are performed. Previously all checks were performed regardless if the result will fail. It also improves readability of the resolve_guid method and moves logic of deciding which provider is what to PlexGuid class for enculapsing logic there.

Requires:

• Feature: Skip livetv events from watch command #777