android: Add various network/room related capabilities (private/public room creation/joining and public lobby browsing)

[OpenSauce04]

Re-opened from #667

This adds the ability for users on Android to play "multiplayer" aka LAN play like QT has been able to do for years via rooms
Experimental testing done by various users shows it to be in a good spot, but here is what is left to do before this PR can be considered ready for review

To access this, you can go to the home settings or the emulation drawer, since this can also work in-game

• Add the ability to select preferred game from room creation
  • Right now it just puts an empty string as a placeholder
• Add the ability to put a room description and read other room descriptions
• Be able to block certain people's chat messages
• Add public room creation support
• Add currently played game details to joined user entries in the lobby
• Handle usernames better
• Test this on multiple games and fix kernel thread / sync issues (help wanted)
  • Some games are crashing with kernel thread errors if the in-game LAN room is hosted on Android
• Cleanup unused leftovers

Closes #509
And
Closes #208

Some UX Screenshots:

Initial dialog:

Room Creation Dialog (Still not finished, see tasks):

Public room browser:

Once you joined in a room: