Scrimmaging Page

[lowtorola]

Adds a scrimmaging page!

[lowtorola]

Convo at meeting 9/30:

• Want to refactor BattlecodeTable usages into e.g. RecentTournamentMatchesTable.tsx
• ^^ will require new subfolders e.g. Scrimaging in components
• Want to refactor new InboxOutbox component
• Move fetch functions into useEffects, set loading above functions, and use destructors to prevent race conditions (see EpisodeProvider)