Champion ID added

I added the Champion ID field to the Match data type, and Match
Repository/Stat Controller now use this data as well when creating
Matches. When new champions are added but LoLStatTracker is not updated,
the ChampID will act as a placeholder until the actual champion name is
included in a future update.
Champ Icon displayed by ID and not string

I changed MatchCellRenderer to choose a champ icon based on ID instead
of champ name. The match json is updated to include a 'get by champion
id' search query.