Remove asmref usage from main SRP code

Currently in Unity 6, asmref files are sometimes used to bypass assembly visibility rules. In the future, asmref is no longer allowed so the current usage must be removed (see [RFC](https://docs.google.com/document/d/1SWAG19Ns5gnmbVl4WD-HT0f4DO2UVdiRj_YhX1o7J7E/edit#heading=h.9tfgs0fpr1tb)). 

This PR solves the sub-task [Remove asmref usage in main SRP package code](https://jira.unity3d.com/browse/XPIPELINE-917), part of the broader task [XPIPELINE-904](https://jira.unity3d.com/browse/XPIPELINE-904) to completely remove asmref usage from SRP code.

Asmref usage in this PR originated from the need to access the internal "rawRenderQueue" property inside Material class. This PR just makes that property public API. Similar code was also found in ShaderGraph and fixed the same way.

Author: arttu-peltonen

Packages/com.unity.render-pipelines.universal/Editor/ShaderGUI/BaseShaderGUI.cs

@@ -846,8 +846,7 @@ internal static void UpdateMaterialRenderQueueControl(Material material)
             // user has explicitly selected a render queue and we should not override it.
             //
             bool isShaderGraph = material.IsShaderGraph(); // Non-shadergraph materials use automatic behavior
-            int rawRenderQueue = MaterialAccess.ReadMaterialRawRenderQueue(material);
-            if (!isShaderGraph || rawRenderQueue == -1)
+            if (!isShaderGraph || material.rawRenderQueue == -1)
             {
                 material.SetFloat(Property.QueueControl, (float)QueueControl.Auto); // Automatic behavior - surface type override
             }

Packages/com.unity.render-pipelines.universal/Editor/ShaderGUI/MaterialAssemblyReference.meta

@@ -3,13 +3,9 @@
 using UnityEditor;
 using UnityEditor.ProjectWindowCallback;
 using System.IO;
-using UnityEditorInternal;
 using ShaderKeywordFilter = UnityEditor.ShaderKeywordFilter;
 #endif
 using System.ComponentModel;
-using System.Linq;
-using UnityEditor.Rendering;
-using UnityEngine;
 using UnityEngine.Serialization;
 using UnityEngine.Experimental.Rendering;
 using UnityEngine.Rendering.RenderGraphModule;

Packages/com.unity.render-pipelines.universal/Editor/ShaderGUI/MaterialAssemblyReference/MaterialAssemblyReference.asmref

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using UnityEditor.Rendering;
 using UnityEngine.Experimental.Rendering;
 
 namespace UnityEngine.Rendering.Universal

Packages/com.unity.render-pipelines.universal/Editor/ShaderGUI/MaterialAssemblyReference/MaterialAssemblyReference.asmref.meta

@@ -2,9 +2,11 @@
 using System.IO;
 using System.ComponentModel;
 using System.Collections.Generic;
+using UnityEngine.Serialization;
+#if UNITY_EDITOR
 using UnityEditor;
 using UnityEditor.Rendering;
-using UnityEngine.Serialization;
+#endif
 
 namespace UnityEngine.Rendering.Universal
 {

Packages/com.unity.render-pipelines.universal/Editor/ShaderGUI/MaterialAssemblyReference/RawRenderQueue.cs

@@ -209,8 +209,7 @@ internal static void UpdateMaterialRenderQueueControl(Material material)
             // If we find another value, add the the property set to 1 so we will know that the
             // user has explicitly selected a render queue and we should not override it.
             //
-            int rawRenderQueue = MaterialAccess.ReadMaterialRawRenderQueue(material);
-            if (rawRenderQueue == -1)
+            if (material.rawRenderQueue == -1)
             {
                 material.SetFloat(Property.QueueControl(), (float)QueueControl.Auto); // Automatic behavior - surface type override
             }