System for servers to announce additional capabilities

[rcelyte]

BeatUpServer supports a few special features not available in Vanilla, namely per-player difficulty, per-player modifiers, and skipping the results pyramid. It would be nice to have some form of indication on Server Browser for when these are enabled.
I'd like to have a MultiplayerCore packet for the server to send, listing off such capabilities.

[cubicgraphics]

I am currently working on BT server config packets and alike things, it's a wip, atm, but I'm thinking of giving them a different packet group to mpcore packets, like dedi server sub packets or something similar. I also have a BT server API in the works, that I believe bssb is going to make use of which will be able to share public lobbies and etc, also a wip atm.