CORE-4720 Fix for Workspace app count in app-groups.

If a user favorites their own public apps, then the virtual-count added to the user's Workspace template_count would be incorrect in the /secured/app-groups endpoint results.
Updated add-virtual-groups to replace the user's Workspace template_count with the results of the database query call, count-apps-in-group-for-user.
Minor get-only-app-groups refactor.

Refactored get-only-app-groups to accept an integer workspace-id instead of a string.