Make allies spawn near each other in team games

[WilliamWeberBerrutti]

It should be interesting for allies to spawn near each other automatically, like it happens in games like AoE2 or Starcraft 2. I personally think it's a frustrating experience when allies are all scattered around the map, and that can give teams disadvantage based on RNG.

[Mailaender]

See https://github.com/OpenRA/OpenRA/issues/3099