Load bullet part regions (#7663)

* Load bullet part regions

* Unnecessary, just use name in the part

core/src/mindustry/entities/bullet/BasicBulletType.java

@@ -38,6 +38,8 @@ public class BasicBulletType extends BulletType{
 
     @Override
     public void load(){
+        super.load();
+
         backRegion = Core.atlas.find(backSprite == null ? (sprite + "-back") : backSprite);
         frontRegion = Core.atlas.find(sprite);
     }

core/src/mindustry/entities/bullet/BulletType.java

@@ -301,6 +301,14 @@ public class BulletType extends Content implements Cloneable{
         }
     }
 
+    @Override
+    public void load(){
+        for(var part : parts){
+            part.turretShading = false;
+            part.load(null);
+        }
+    }
+
     /** @return estimated damage per shot. this can be very inaccurate. */
     public float estimateDPS(){
         float sum = damage + splashDamage*0.75f;