Permit displaying additional map info, such as TMX IDs

[Phlarx]

May be useful for streamers with viewers looking to download the map.

Possible additional info to consider:

• MX/TMX ID
  • useful and relatively easy to add, but relies on info external to the game
• Map weight (coppers)
  • unlikely to be very useful, existed on TMNF/TMUF UI but removed since
• Map ratings, from TMX or elsewhere
  • better leave that to dedicated plugins, I want to keep this as lightweight as possible
• Creation date
  • mildly useful for the ice changes, or other future physics tweaks, but low importance