Add master stereo disable switch to HDRP

ScriptableRenderPipeline/HDRenderPipeline/Editor/HDRenderPipelineInspector.Styles.cs

             public readonly GUIContent useForwardRenderingOnly = new GUIContent("Use Forward Rendering Only");
             public readonly GUIContent useDepthPrepassWithDeferredRendering = new GUIContent("Use Depth Prepass with Deferred rendering");
             public readonly GUIContent renderAlphaTestOnlyInDeferredPrepass = new GUIContent("Alpha Test Only");
+            public readonly GUIContent disableStereoPaths = new GUIContent("Disable Stereo Paths");
 
             // Texture Settings
             public readonly GUIContent textureSettings = new GUIContent("Texture Settings");

ScriptableRenderPipeline/HDRenderPipeline/Editor/HDRenderPipelineInspector.cs

         SerializedProperty m_RenderingUseForwardOnly;
         SerializedProperty m_RenderingUseDepthPrepass;
         SerializedProperty m_RenderingUseDepthPrepassAlphaTestOnly;
+        SerializedProperty m_RenderingDisableStereoPaths;
 
         // Subsurface Scattering Settings
         SerializedProperty m_SubsurfaceScatteringSettings;
             m_RenderingUseForwardOnly = properties.Find(x => x.renderingSettings.useForwardRenderingOnly);
             m_RenderingUseDepthPrepass = properties.Find(x => x.renderingSettings.useDepthPrepassWithDeferredRendering);
             m_RenderingUseDepthPrepassAlphaTestOnly = properties.Find(x => x.renderingSettings.renderAlphaTestOnlyInDeferredPrepass);
+            m_RenderingDisableStereoPaths = properties.Find(x => x.renderingSettings.disableStereoPaths);
 
             // Subsurface Scattering Settings
             m_SubsurfaceScatteringSettings = properties.Find(x => x.sssSettings);
                     EditorGUI.indentLevel--;
                 }
             }
+
+            EditorGUILayout.PropertyField(m_RenderingDisableStereoPaths, s_Styles.disableStereoPaths);
 
             EditorGUI.indentLevel--;
         }

ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.cs

         public bool useForwardRenderingOnly; // TODO: Currently there is no way to strip the extra forward shaders generated by the shaders compiler, so we can switch dynamically.
         public bool useDepthPrepassWithDeferredRendering;
         public bool renderAlphaTestOnlyInDeferredPrepass;
+        public bool disableStereoPaths;
 
         // We have to fall back to forward-only rendering when scene view is using wireframe rendering mode --
         // as rendering everything in wireframe + deferred do not play well together
             {
                 HDCamera.CleanUnused();
                 m_FrameCount = Time.frameCount;
+            }
+
+            bool stereoActive = false && !m_Asset.renderingSettings.disableStereoPaths;
+            if (stereoActive)
+            {
+                m_VolumetricLightingEnabled = false; // XRTODO: Implement VL
             }
 
             // This is the main command buffer used for the frame.