Improve web UI: sort/search/context menu, fix security and UX bugs

templates/buckets.html

@@ -89,6 +89,14 @@
     </div>
   </div>
   {% endfor %}
+  <div class="col-12 d-none" id="bucket-no-results">
+    <div class="text-center py-5 text-muted">
+      <svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" fill="currentColor" class="mb-3 opacity-50" viewBox="0 0 16 16">
+        <path d="M11.742 10.344a6.5 6.5 0 1 0-1.397 1.398h-.001c.03.04.062.078.098.115l3.85 3.85a1 1 0 0 0 1.415-1.414l-3.85-3.85a1.007 1.007 0 0 0-.115-.1zM12 6.5a5.5 5.5 0 1 1-11 0 5.5 5.5 0 0 1 11 0z"/>
+      </svg>
+      <p class="mb-0 fw-medium">No buckets match your filter.</p>
+    </div>
+  </div>
 </div>
 
 <div class="modal fade" id="createBucketModal" tabindex="-1" aria-hidden="true">
@@ -149,6 +157,15 @@
             item.classList.add('d-none');
           }
         });
+
+        var noResults = document.getElementById('bucket-no-results');
+        if (noResults) {
+          if (term && visibleCount === 0) {
+            noResults.classList.remove('d-none');
+          } else {
+            noResults.classList.add('d-none');
+          }
+        }
       });
     }