Time Trial mode has been added as a new standalone mode

New Features:
- Added time trial mode that features 4 different tracks to compete in each week
- Engine mode consumption speed has been added in the party lobby

Changes:
- Manager mode has been removed from duel mode to reduce player segregation. It now only exists in the party lobby.
- Public and Private lobbies have been merged to reduce player segregation
- Users in duel mode now match with an AI if a user is not found for 300 seconds instead of 60
- #community-events channel has its own button in the Game Modes menu screen.

Bug Fixes:
- Assist button did not appear if a user played a game in the manager mode followed by player mode