Fix cloth with MeshOptimization ON

- Reexport cloth assets with AssImp ON. These was necessary because AssImp collects a different name for the color streams than FbxSDK and therefore they needed to be reassigned in the cloth rule.
- Adding '_optimized' string to a global variable and using StringFunc RChop to remove it for a string.

Code/Tools/SceneAPI/SceneCore/Utilities/SceneGraphSelector.cpp

@@ -47,7 +47,7 @@ namespace AZ
             Containers::SceneGraph::NodeIndex SceneGraphSelector::RemapToOptimizedMesh(const Containers::SceneGraph& graph, const Containers::SceneGraph::NodeIndex& index)
             {
                 const auto& nodeName = graph.GetNodeName(index);
-                const AZStd::string optimizedName = AZStd::string(nodeName.GetPath(), nodeName.GetPathLength()) + "_optimized";
+                const AZStd::string optimizedName = AZStd::string(nodeName.GetPath(), nodeName.GetPathLength()).append(OptimizedMeshSuffix);
                 if (auto optimizedIndex = graph.Find(optimizedName); optimizedIndex.IsValid())
                 {
                     return optimizedIndex;

Code/Tools/SceneAPI/SceneCore/Utilities/SceneGraphSelector.h

@@ -22,6 +22,8 @@ namespace AZ::SceneAPI::DataTypes { class ISceneNodeSelectionList; }
 
 namespace AZ::SceneAPI::Utilities
 {
+    inline constexpr AZStd::string_view OptimizedMeshSuffix = "_optimized";
+
     // SceneGraphSelector provides utilities including converting selected and unselected node lists
     // in the MeshGroup into the final target node list.
     class SceneGraphSelector