#3489354 Connect the "Publish" button with the entity update controller

Closes #3489354

ui/src/components/topbar/Topbar.module.css

@@ -42,3 +42,20 @@
     height: 100%;
   }
 }
+
+.loading {
+  padding-right: 10px;
+}
+.loading::after {
+  position: absolute;
+  overflow: hidden;
+  width: 0;
+  content: "\2026";
+  animation: ellipsis steps(4, end) 900ms infinite;
+}
+
+@keyframes ellipsis {
+  to {
+    width: 1.25em;
+  }
+}