refactor(srp): bind managed native scene renderers per renderer selection

managed/XCEngine.ScriptCore/Rendering/Core/ScriptableRenderPipelineAsset.cs

@@ -52,6 +52,12 @@ namespace XCEngine.Rendering
             return string.Empty;
         }
 
+        protected virtual string GetPipelineRendererAssetKeyContextual(
+            int rendererIndex)
+        {
+            return GetPipelineRendererAssetKey();
+        }
+
         protected virtual void ReleaseRuntimeResources()
         {
         }