Chat filter

[spazzylemons]

Chat should be filtered such that spectators cannot see messages from players and vice versa, and should also be filtered per world so chat messages stay in the game they are sent in. There is an attempted implementation of this, but it does not work and is incomplete.

[spazzylemons]

For anyone wanting to do this: wait until StickyChat v4 is ready so we can use the new events, and don't forget to pull, the branch I created to implement this on, feat/spazzylemons/chat_filter, is very out of date.