Unrar support

This commit adds unrar support to the renamer. Note that only movies that are found in snatched status by ID or that are requested by an API call providing the movie_folder are processed. It follows the (sym)link philosophy, but does remove extracted files after renaming.

The behavior can in theory be extended to also work with the force scan / blackhole scan of the 'from' folder. I, however, got stuck with tagging in combination with linking to make sure we dont do things twice...