Added admin screen for event registrations
Closes #88
Short description
Added admin screen for event registrations
Steps to use this feature
- Open an event that has registrations and for which you are an organiser (or any event with registrations if you are superuser).
- Press the settings icon at the top right.
- Notice you encounter a list with all registrations for this event, in which you can:
- Mark whether a member is present
- If (and how) a member has paid
- Search for participants
- Filter the list of registrations on payment status or presence
As with the website admin through which this is currently done, all information is immediately updated in the background. Updating the list can be done using the pull-to-refresh functionality.