Set reports as handled

[DeveloperCallum]

Is your feature request related to a problem? Please describe.
It currently is impossable to tell if a report has been handled by another user. this could cause multiple staff to handle the same request.

Describe the solution you'd like
if someone handles a report the embed is updated to say REPORT HANDLED BY X STAFF.

Describe alternatives you've considered
None.

[danthe1st]

possible implementation:
I think we should (a) replace the report deletion button with a button marking the report as handled, (b) make the kick/ban buttons mark the report as handled and (c) add a button that warns the user (using a modal)

[MoonTM-GIT]

Yup, I like that