Finish the events system

[liessdow]

The events system needs the following:

• [x] Ability for staff to make an event and view controller applications, and delete them
• [x] Ability for staff to edit details of events
• [x] this
• [ ] add extra stuff as another dotpoint if you want

[liessdow]

and it's done! https://github.com/gander-oceanic-fir-vatsim/czqo-core/commit/157c3656f75e8af9f7faafa62f9ad245eb1bc355