Adds basic camp generation and placement logic to the map generation process.
It attempts to place the camp in a valid location, avoiding paths and water bodies. It also sets the player's spawn point to the center of the generated camp, including some basic camp props like a tent, campfire, and bed.
Additionally, vegetation spawning is now dependent on the `should_spawn_*` methods of the `CellDataResource`, allowing more control over what spawns where.
