Multi instance support

[M3th0s]

Support multiple arr instances.

The way I see it, two ways of achieving this:

• allow for Plex section id being added to the config. That way you can have separate eraserr instances running pointing to two separate arrs and only going through relevant Plex directories or
• allow for multiple arr instance in the config. That way, one sweep will look up all relevant media and delete from specific arr instance

Thanks in advance and much appreciated for all the work so far !