calculate weights for on_initialize

[bernardoaraujor]

on_initialize needs to return its consumed weight.

currently, there's no upper bound on the amount of ongoing matches. since on_initialize iterates over all matches, there's no upper bound on the maximum possible weight to be consumed.

todo:

• a new Config type MaxOngoingMatches: Get<u32>
• a new StorageValue called MatchCounter
• logic increasing or decreasing MatchCounter when appropriate
• a check inside create_match verifying whether MatchCounter <= MaxOngoingMatches::get()

[lana-shanghai]

Suggestion to get rid of the on_initialize hook: add an extrinsic that a player can call to win the game and retrieve the deposit from both players, if the opponent's time to make a move has expired.

[bernardoaraujor]

closed via #15 and #16