Allow players to join mid game and fix away players from being pulled into a race

[derole1]

As the title suggests

Currently WIP need to set myself up a dev environment first to see if I can figure this out

[derole1]

In regards to the above commit, we still need to account for players who are away getting assigned host, as they then cannot toggle this back off until they are no longer host again. The server controls host state (I think) so its possible that we just force the player into non-away status when being appointed host, or just do not select them when auto selecting a host if the game blocks setting an away person as host.

Also need to figure out what the game does if everyone leaves the lobby apart from the away person, who does host get assigned to then?

[derole1]

This seems to work after some preliminary testing, the matchmaking filter is difficult to test without a lot of players so going to push this onto live but I cant see why it wouldnt work and it does not crash the game at all. It is definetly taken into account by the game according to TTY logs however.