Done Redirect private battle links to public battles

[Felucia]

Right now, if someone links a game (eg battle-gen91v1-2077664670-8zadxc628mk1nefspwi1jvc2pvbwo6spw) attempting to join it will fail if /publicroom was used, because the new room name is battle-gen91v1-2077664670. I suggest automatically attempting to strip the 8zadxc628mk1nefspwi1jvc2pvbwo6spw part off links when joining battles.

 

[DaWoblefet]

Done by Karthik: https://github.com/smogon/pokemon-showdown/pull/10204