Make payload blocks run onDestroyed() of the block payload it carries when destroyed. (#8253)

* Payloads go boom.

* When a payload unit dies too

* Keep the functionality, but limit it to a rule

core/src/mindustry/world/blocks/payloads/BuildPayload.java

@@ -51,6 +51,11 @@ public class BuildPayload implements Payload{
         build.updatePayload(unitHolder, buildingHolder);
     }
 
+    @Override
+    public void destroyed(){
+        build.onDestroyed();
+    }
+
     @Override
     public ItemStack[] requirements(){
         return build.block.requirements;

core/src/mindustry/world/blocks/payloads/Payload.java

@@ -54,6 +54,8 @@ public interface Payload extends Position{
         return 0f;
     }
 
+    default void destroyed(){};
+
     /** writes the payload for saving. */
     void write(Writes write);
 

core/src/mindustry/world/blocks/payloads/PayloadBlock.java

@@ -151,6 +151,12 @@ public class PayloadBlock extends Block{
             }
         }
 
+        @Override
+        public void onDestroyed(){
+            if(payload != null) payload.destroyed();
+            super.onDestroyed();
+        }
+
         public boolean blends(int direction){
             return PayloadBlock.blends(this, direction);
         }

core/src/mindustry/world/blocks/payloads/PayloadConveyor.java

@@ -190,6 +190,12 @@ public class PayloadConveyor extends Block{
             super.draw();
         }
 
+        @Override
+        public void onDestroyed(){
+            if(item != null) item.destroyed();
+            super.onDestroyed();
+        }
+
         @Override
         public void draw(){
             super.draw();