Rooms management page

Allow to create/modify/remove rooms.

changed time estimate to 4h

assigned to @jacek.lebioda

Started

mentioned in merge request !118 (merged)

Basic functionality already there. UX corrections (if any) and tests left.

Tests (200/302 + success of CRUD) are implemented and passing. Can be merged after confirmation that it is acceptably functional.

Handling of Items could be done slightly better - e.g. inside the Room management itself, similar to the Django admin's + sign close to the multi-select boxes.

mentioned in merge request !123 (merged)

closed via commit b7072c6e

closed via merge request !123 (merged)