Update getContentItems to return total count and items

The changes involved modifying the implementation of `getContentItems` across multiple files, specifically in the CMS-related codebase. This method now returns an object containing the total count of items and the items themselves. The updates also included necessary adjustments in the code where `getContentItems` is called to accommodate the new structure of the returned result.

apps/web/app/(marketing)/blog/page.tsx

@@ -23,7 +23,7 @@ async function BlogPage({ searchParams }: { searchParams: { page: string } }) {
   const limit = 10;
   const offset = page * limit;
 
-  const posts = await cms.getContentItems({
+  const { items: posts, total } = await cms.getContentItems({
     collection: 'posts',
     limit,
     offset,