made buildings require base provider (be in build radius)

Rationale:
Engineers right now can capture a building and then start building turrets in your base. Some might view this as legitimate but it is a pretty ridiculous strategy and makes game kind of unfun.
Part of why it's a problem is that turrets are quite powerful in this mod, and hard to kill.
The build radius is set to 30, which is very high, so it shouldn't be noticeable for most players in most games. But it will stop you from being able to build across the map.

mods/d2k/rules/defaults.yaml

@@ -180,6 +180,7 @@
 	TargetableBuilding:
 		TargetTypes: Ground, C4
 	Building:
+		RequiresBaseProvider: true
 		Dimensions: 1,1
 		Footprint: x
 		TerrainTypes: Rock, Concrete