Add `deployUrl` for cloud

Importing relative assets from components will get them output to the
deployPath and prepended with the `deployUrl`.

This unfortunately is static, and not supported with our
RELATIVE_URL_ROOT rails option, which currently does not trigger
compilation.

On cloud, this is not a problem so enabling this option for the
subscription plugin

frontend/angular.json

@@ -14,6 +14,7 @@
           "options": {
             "preserveSymlinks": true,
             "aot": true,
+            "deployUrl": "/assets/frontend/",
             "outputPath": "../public/assets/frontend/",
             "index": "src/index2.html",
             "main": "src/main.ts",
@@ -155,4 +156,4 @@
   "cli": {
     "analytics": false
   }
-}
+}