Extract date rendering into per-feature Date components

Elternbeirat.Web/Features/Posts/PostList.razor

@@ -19,9 +19,7 @@ else
         {
             <li>
                 <a href="@($"/posts/{post.Slug}")">@post.Title</a>
-                <time datetime="@post.Date.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture)">
-                    @post.Date.ToString("d. MMMM yyyy", Cultures.German)
-                </time>
+                <PostDate Value="post.Date" />
             </li>
         }
     </ul>