Returns the key and value of an app's property. The property key connect_client_key_019cdff3-8bfb-71fe-9628-875b700aebb8
is reserved. It returns a synthetic, read-only property containing the Connect clientKey for the requested tenant.
This is intended for Forge apps with app.connect.key to retrieve the Connect client key during migration.
required: Only a Connect app whose key matches addonKey can make this request.
Additionally, Forge apps can access Connect app properties (stored against the same app.connect.key).