Renamed search and add functions for Steam to _handle_steam_*, Added
ItchIO handlers
Updated Steam Add to check and see if we have already fetched the App
information, and if so, use it, otherwise try to search. *Note* Need to
clear after adding, so we don't accidently add to the wrong user, and
need to validate if the game has already been added or not.
Added Logic to for ItchIO.
