[VFX] Fixed wrong node type in CurlNoise variant

Jira: [UUM-72985](https://jira.unity3d.com/browse/UUM-72985)

1. Create project using High Definition 3D Template
2. Create VFX Asset and open it
3. In New VFX window press space or right-click to open VFX Node Search Window
4. In the Search field type “Curl”
5. From the panel double click on “Value Curl Noise 2D”
6. Observe the Console window

Actual results: Error “ArgumentException: Object of type 'UnityEditor.VFX.Operator.CurlNoise+DimensionCount' cannot be converted to type 'UnityEditor.VFX.Operator.Noise+DimensionCount’.”
Expected results: No errors are thrown in the Console, Node is added to the VFX Workspace

Reproducible with versions: 17.0.3 (6000.0.1f1, 6000.0.4f1)
Not reproducible with versions: 17.0.3 (6000.0.0f1)

Tested on (OS): MacBook Pro, 2021. Sonoma 14.4.1 (M1)

Author: julienamsellem

Packages/com.unity.visualeffectgraph/Editor/Models/Operators/Implementations/CurlNoise.cs

@@ -31,7 +31,7 @@ public override IEnumerable<Variant> GetVariants()
                     yield return new Variant(
                         type.ToString().Label().AppendLiteral("Curl Noise").AppendLabel(VFXBlockUtility.GetNameString(dimension)),
                         category,
-                        typeof(Noise),
+                        typeof(CurlNoise),
                         new[]
                         {
                             new KeyValuePair<string, object>("type", type),

Tests/SRPTests/Projects/VisualEffectGraph_HDRP/Assets/AllTests/Editor/Tests/VFXGUITests.cs

@@ -395,7 +395,11 @@ public void ExpandRetractAndSetPropertyValue()
         public void CreateAllOperatorsTest()
         {
             var viewController = VFXTestCommon.StartEditTestAsset();
-            Assert.DoesNotThrow(() =>CreateAllOperators(viewController));
+            Assert.DoesNotThrow(() =>
+            {
+                var operators = CreateAllOperators(viewController);
+                Debug.Log($"Created {operators.Length} operators");
+            });
         }
 
         [UnityTest]
@@ -434,6 +438,7 @@ public IEnumerator CollapseTest()
         VFXOperator[] CreateAllOperators(VFXViewController viewController)
         {
             return VFXLibrary.GetOperators()
+                .SelectMany(x => new [] {x}.Concat(x.subVariantDescriptors))
                 .Select((x, i) => viewController.AddVFXOperator(new Vector2(700, 150 * i), x.variant))
                 .ToArray();
         }
@@ -1009,14 +1014,16 @@ private static VFXModelDescriptor<VFXBlock>[] GetAllBlocks(bool filterOut, Predi
             {
                 return VFXLibrary.GetBlocks()
                     .Where(x => predicate(x))
-                    //.GroupBy(x => x.category)
-                    //.Select(x => x.First())
+                    .SelectMany(x => new [] { x }.Concat(x.subVariantDescriptors))
+                    .Cast<VFXModelDescriptor<VFXBlock>>()
                     .ToArray();
             }
             else
             {
                 return VFXLibrary.GetBlocks()
                     .Where(x => predicate(x))
+                    .SelectMany(x => new [] { x }.Concat(x.subVariantDescriptors))
+                    .Cast<VFXModelDescriptor<VFXBlock>>()
                     .ToArray();
             }
         }