Add last activity at into main user app and API

When you view "My workspaces" you can see last activity date per workspace. This information is missing from main user app workspaces -view and also from our Partner API.

It would be very beneficial in both of these views, since they can be used to decide if workspace still has active usage.

Also if possible, it would be nice to see "last login" information on both of these locations (main user app and API).