Mesh Component: Add button to the Mesh Asset field to open mesh FBX settings (#7547)

This is an UX improvement for Mesh Component as the user can quickly access FBX settings of the mesh to modify it if they so desire.

Video
https://user-images.githubusercontent.com/27999040/153414278-f7996b9a-8a28-49d4-92a8-daeb9924b148.mp4

Signed-off-by: moraaar moraaar@amazon.com

Gems/Atom/RPI/Code/Source/RPI.Reflect/Model/ModelAsset.cpp

@@ -15,6 +15,7 @@
 
 #include <AzCore/RTTI/ReflectContext.h>
 #include <AzCore/Serialization/SerializeContext.h>
+#include <AzCore/Serialization/EditContext.h>
 
 namespace AZ
 {
@@ -35,6 +36,15 @@ namespace AZ
                     ->Field("MaterialSlots", &ModelAsset::m_materialSlots)
                     ->Field("LodAssets", &ModelAsset::m_lodAssets)
                     ;
+
+                // Note: This class needs to have edit context reflection so PropertyAssetCtrl::OnEditButtonClicked
+                //       can open the asset with the preferred asset editor (Scene Settings).
+                if (auto* editContext = serializeContext->GetEditContext())
+                {
+                    editContext->Class<ModelAsset>("Model Asset", "")
+                        ->ClassElement(AZ::Edit::ClassElements::EditorData, "")
+                        ;
+                }
             }
         }