fix: Allow the mode setup/creation to be async, and provide a few more values to extension/app config/mode setup. (#4016)

lerna.json

@@ -1,5 +1,5 @@
 {
   "version": "3.9.0-beta.46",
-  "packages": ["extensions/*", "platform/*", "modes/*"],
+  "packages": ["extensions/*", "platform/*", "modes/*", "addOns/externals/*"],
   "npmClient": "yarn"
 }