openDesk modules and custom portal icons/tiles

The openDesk (standard) portal tiles are rendered based on the user's managed-by-attribute-* groups, these are managed by user attributes that are set based on the selection in a user's "openDesk" tab.

To have a better (admin) user experience we want to:

• only add (not remove) settings for the installed components to the user's (and group's) "openDesk" tab.
• only add (not remove) managed-by-attribute-* groups that have corresponding components installed.
• ensure the standard openDesk user template only uses available attributes.
• allow a customer/instance admin to manage custom/additional tiles in the portal (allow toggling the portal edit mode by a deployment flag).