Add server tick events for BlockEntity, Chunk, and Entity

[forgetmenot13579]

Also adds tests for the new (and existing) chunk events.

[modmuss50]

Is this something we really want? In the past we have said no as they are a very common cause of peformance issues.

[forgetmenot13579]

The people who need this functionality are going to mixin anyway. By adding these events, we will have load, tick, and unload events for all four AttachmentTarget types and can look at implementing some kind of component system on top as previously discussed in the Discord server.

[modmuss50]

A mixin is likely a better solution here, as it allows you to inject into the specific entity at the specific time that suits a modders need. One idea I had for these kinds of events would be registering them to the target when its loaded however this has its own issues.

On a large servers there are going to vast numbers of BE's, chunks and entities loaded at once, its going to be way too easy for someone to bring the server to a crawl.