Launch game

[Apolixit]

Prerequisite : Matchmaking pallet
Once matchmaking pallet is integrated, we need to launch an OnChain game to play against opponents in the queue

Goal :

1. Click on "Play" button to enter into matchmaking and selected between 2 and 4 players to play against
2. Display a screen (new Substate Unity component) with "X players are currently waiting"
3. When amount of players is reached, launch the game
4. Add cancel button to leave the queue (20 second cooldown ?)