Add a 7-day activity overview to group overview page
This is something we're still getting feedback on (2nd iteration - ux-research#139 (closed)) but the first iteration received very positive feedback (ux-research#113 (closed)) so we should consider adding a 7-day overview to group page overview.
Overview breakdwon:
The plan right now is:
- get more feedback on 2nd iteration (ux-research#139 (closed))
- schedule implementation