feat: add team feature flag (#915)

## Description

Add the ability to feature flag the teams feature via UI.

Also added minor UI changes

## Checklist

- [X] I have tested these changes locally and they work as expected.
- [X] I have added/updated tests that prove the effectiveness of these
changes.
- [X] I have followed the project's coding style guidelines.

packages/lib/constants/feature-flags.ts

@@ -17,6 +17,7 @@ export const FEATURE_FLAG_POLL_INTERVAL = 30000;
  */
 export const LOCAL_FEATURE_FLAGS: Record<string, boolean> = {
   app_billing: process.env.NEXT_PUBLIC_FEATURE_BILLING_ENABLED === 'true',
+  app_teams: true,
   marketing_header_single_player_mode: false,
 } as const;