Update JS dependencies (#10450)

Fomantic's update process did fail to update via 'npm install' because
of our config initially but it did work after manually bumping the
version in semantic.json.

Fomantic changes:

https://github.com/fomantic/Fomantic-UI/blob/master/CHANGELOG.md#284

semantic.json

@@ -1,5 +1,5 @@
 {
-  "version": "2.8.3",
+  "version": "2.8.4",
   "base": "node_modules/fomantic-ui",
   "paths": {
     "source": {