Moved resource load to HDEditorUtils

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/HDLightEditor.cs

                 switch (m_LightShape)
                 {
                     case LightShape.Rectangle:
-                        emissiveMeshFilter.mesh = AssetDatabase.LoadAssetAtPath< Mesh >(HDEditorUtils.GetHDRenderPipelinePath() + "RenderPipelineResources/Quad.FBX");
+                        emissiveMeshFilter.mesh = HDEditorUtils.LoadAsset< Mesh >("RenderPipelineResources/Quad.FBX");
                         lightGameObject.transform.localScale = new Vector3(lightData.shapeWidth, lightData.shapeHeight, 0);
                         areaLightIntensity = LightUtils.ConvertRectLightIntensity(
                             light.intensity,

com.unity.render-pipelines.high-definition/HDRP/Editor/RenderPipeline/HDEditorUtils.cs

             return "Packages/com.unity.render-pipelines.core/CoreRP/";
         }
 
+        public static T LoadAsset<T>(string relativePath) where T : UnityEngine.Object
+        {
+            return AssetDatabase.LoadAssetAtPath<T>(GetHDRenderPipelinePath() + relativePath);
+        }
+
         public static bool ResetMaterialKeywords(Material material)
         {
             MaterialResetter resetter;