Add a way to leave the FFA when you're already down there, e.g automatically relogging

Hello.
Automatically relogging doesn't work since it puts the player back in FFA. So the only other way to do this is executing /spawn and then /hub.
/spawn takes 7 seconds before teleporting, so I don't see a rationale in automatic execution of /hub after teleporting - type it in the meantime.
I also asked a few FFA players and none of them had any need for this, so I don't see any reason to implement this.

If you'd like to PR this (don't worry if you don't), the way I see it could be done is a /hub-force (or suggest a better name!) which would do what I kinda described above.
I think a command is the best way to do it since it can interoperate with other mods like Command Macros.
You'd need to see if the player is in FFA too, check out the PvPLegacyUtilsAPI for that.
I'd prefer if the command didn't show in other locations, but if that's not reasonably/technologically possible I'd be fine with it regardless.

Contributing is optional, of course. For now, I'm closing this as not planned. Feel free to ask any further questions.