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.

apps/web/src/components/(dashboard)/settings/layout/mobile-nav.tsx

@@ -19,6 +19,7 @@ export const MobileNav = ({ className, ...props }: MobileNavProps) => {
   const { getFlag } = useFeatureFlags();
 
   const isBillingEnabled = getFlag('app_billing');
+  const isTeamsEnabled = getFlag('app_teams');
 
   return (
     <div
@@ -38,18 +39,20 @@ export const MobileNav = ({ className, ...props }: MobileNavProps) => {
         </Button>
       </Link>
 
-      <Link href="/settings/teams">
-        <Button
-          variant="ghost"
-          className={cn(
-            'w-full justify-start',
-            pathname?.startsWith('/settings/teams') && 'bg-secondary',
-          )}
-        >
-          <Users className="mr-2 h-5 w-5" />
-          Teams
-        </Button>
-      </Link>
+      {isTeamsEnabled && (
+        <Link href="/settings/teams">
+          <Button
+            variant="ghost"
+            className={cn(
+              'w-full justify-start',
+              pathname?.startsWith('/settings/teams') && 'bg-secondary',
+            )}
+          >
+            <Users className="mr-2 h-5 w-5" />
+            Teams
+          </Button>
+        </Link>
+      )}
 
       <Link href="/settings/security">
         <Button