Updated KAT search to grab torrents sooner

The KAT search has been using the advanced-search format, which often doesn't provide any results until several weeks after a show has aired. Check out "Archer (2009)" as an example.

This update adds a secondary search if the default one fails. This search is a bit fuzzier, using the search string format: "Season Name" S01E01 which brings back more results. I've found it to deliver accurate results in testing.

Notes:

Used delegates to keep it dry.
Split out feed parsing into a separate function to aid Single Responsibility.
Also re-enabled the verified:1 parameter.
This is the first time I've ever looked at Python code so happy for feedback of any sort.