Add method to get the number of elements in a model builder (#7792)

src/main/java/net/minecraftforge/client/model/generators/ModelBuilder.java

@@ -199,6 +199,15 @@ public class ModelBuilder<T extends ModelBuilder<T>> extends ModelFile {
         return elements.get(index);
     }
 
+    /**
+     * Gets the number of elements in this model builder
+     * @return the number of elements in this model builder
+     */
+    public int getElementCount()
+    {
+        return elements.size();
+    }
+
     /**
      * Use a custom loader instead of the vanilla elements.
      * @param customLoaderFactory