Convert event based callbacks to use lambdas

[Vurv78]

Certain events would be better represented with callbacks.

I did try to avoid having these events that would be better handled with lambdas, which is why there was never a timer or interval event, but the http and file events were deemed necessary enough to have an event counterpart.

Of course events that make sense globally like tick, chat etc will remain as events.

• http
• file

[Denneisk]

playerMove? Lol.

[Denneisk]

Also now this makes me feel bad for eventifying file even further, but no worries.