Daniel Gerhardt requested to merge admin-area into master Jul 24, 2020

Add an admin area which currently has the following features:

Display system health (backend-core)
Display statistics (backend-core)
Manage users (display properties, activate, delete)
Manage rooms (display properties, transfer, delete)

Depends on

!616 (merged) (only cosmetic, not a hard requirement)
!617 (merged) (only cosmetic, not a hard requirement)
arsnova-backend!261
arsnova-backend!262

Edited Jul 27, 2020 by Daniel Gerhardt