Remove ' (Riot)' from app name

And remove the hacks to make the user data path different from the
app name. Also add the profile dir to the legacy user data dir too.

Fixes https://github.com/vector-im/riot-web/issues/14619
Fixes https://github.com/vector-im/riot-web/issues/14623

package.json

@@ -1,6 +1,6 @@
 {
   "name": "element-desktop",
-  "productName": "Element (Riot)",
+  "productName": "Element",
   "main": "src/electron-main.js",
   "version": "1.7.1",
   "description": "A feature-rich client for Matrix.org",