Remove billing and checkout redirect buttons and related services

Deleted the billing-redirect-button, checkout-redirect-button, and embedded-stripe-checkout components. Additionally, removed the shadcn directory, which encompassed billing-related icons. This change streamlines the subscription settings interface and organizes the system's payment management. This update is a stepping stone towards improving the billing system's overall architecture.

apps/web/app/admin/users/[uid]/components/UserActionsDropdown.tsx

@@ -2,6 +2,7 @@
 
 import Link from 'next/link';
 
+import If from '@/components/app/If';
 import { EllipsisVerticalIcon } from 'lucide-react';
 
 import { Button } from '@kit/ui/button';
@@ -12,8 +13,6 @@ import {
   DropdownMenuTrigger,
 } from '@kit/ui/dropdown-menu';
 
-import If from '@/components/app/If';
-
 function UserActionsDropdown({
   uid,
   isBanned,