gkeys/lib.py: Add optional fingerprint param to list_keys

This changes the task and target info for the gpg search.
gkeys/seed.py: Fix spaces issue,  case sensitivity and inclusion matching

Also fix a traceback if nick was not in the kwargs.
gkeys: Add a gpgsearch cli option, refactor listkey()

Refactor listkey() for consistent output between the gkey search and gpg search output.
Create a separate _list_it() for displaying/returning key info and gpg output.
Perform a gkey lookup from the gpg output fingerprint.
gkeys/actions.py: Remove commented out listkey() code block