Removed unused Qt classes and do some more code clean up

Signed-off-by: srikappa-amzn <srikappa@amazon.com>

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/PrefabEditorEntityOwnershipInterface.h

@@ -56,6 +56,5 @@ namespace AzToolsFramework
         virtual void StopPlayInEditor() = 0;
 
         virtual void CreateNewLevelPrefab(AZStd::string_view filename, const AZStd::string& templateFilename) = 0;
-        virtual bool IsRootTemplateDirty() = 0;
     };
 }

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/PrefabEditorEntityOwnershipService.cpp

@@ -617,11 +617,6 @@ namespace AzToolsFramework
         m_playInEditorData.m_isEnabled = false;
     }
 
-    bool PrefabEditorEntityOwnershipService::IsRootTemplateDirty()
-    {
-        return (m_prefabSystemComponent->IsTemplateDirty(m_rootInstance->GetTemplateId()));
-    }
-
     //////////////////////////////////////////////////////////////////////////
     // Slice Buses implementation with Assert(false), this will exist only during Slice->Prefab
     // development to pinpoint and replace specific calls to Slice system

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/PrefabEditorEntityOwnershipService.h

@@ -196,7 +196,6 @@ namespace AzToolsFramework
         Prefab::TemplateId GetRootPrefabTemplateId() override;
         
         const AZStd::vector<AZ::Data::Asset<AZ::Data::AssetData>>& GetPlayInEditorAssetData() override;
-        bool IsRootTemplateDirty() override;
         //////////////////////////////////////////////////////////////////////////
 
         void OnEntityRemoved(AZ::EntityId entityId);