feat: Option to add compliance add-ons

Apps like ERPNext, HR have compliance add-ons. These can be declared in the `apps.json` (?) and when install app is selected, give an option to add a compliance app as well.

Start by locating the app-install flow and checking whether apps.json is the declaration point suggested in the issue. Trace how the install-app selection is presented, then determine the expected behavior for selecting a compliance add-on alongside an app; done means the option is available and the selected add-on is installed correctly.

Written by the indexing model from the issue text.