Implement shader HelperThreadNV (#2163)

* Implement shader HelperThreadNV

* Bump shader cache version

* Use gl_HelperInvocation since its supported across all vendors

* Nit

Ryujinx.Graphics.Gpu/Shader/ShaderCache.cs

@@ -35,7 +35,7 @@ namespace Ryujinx.Graphics.Gpu.Shader
         /// <summary>
         /// Version of the codegen (to be changed when codegen or guest format change).
         /// </summary>
-        private const ulong ShaderCodeGenVersion = 2147;
+        private const ulong ShaderCodeGenVersion = 2163;
 
         // Progress reporting helpers
         private volatile int _shaderCount;