Implemented #3486 with some minor changes

core/src/mindustry/world/meta/BlockGroup.java

@@ -1,5 +1,16 @@
 package mindustry.world.meta;
 
 public enum BlockGroup{
-    none, walls, projectors, turrets, transportation, power, liquids, drills, storage, units, logic
+    none, walls(true), projectors(true), turrets, transportation(true), power, liquids(true), drills, storage, units, logic(true);
+
+    /** if true, any block in this category replaces any other block in this category. */
+    public final boolean anyReplace;
+
+    BlockGroup(boolean anyReplace){
+        this.anyReplace = anyReplace;
+    }
+
+    BlockGroup(){
+        this(false);
+    }
 }