message: Invoke ion assets tab in level editor tab manager.
diff: #include "UnrealConversions.h"
  #include "IonQuickAddPanel.h"
  #include "CesiumIonPanel.h"
  +#include "LevelEditor.h"
  void CesiumPanel::Construct(const FArguments& InArgs)
  {
  @@ -87,7 +88,9 @@ TSharedRef<SWidget> CesiumPanel::ConnectionStatus() {
  void CesiumPanel::addFromIon()
  {
  - FGlobalTabmanager::Get()->TryInvokeTab(FTabId(TEXT("CesiumIon")));
  + FLevelEditorModule* pLevelEditorModule = FModuleManager::GetModulePtr<FLevelEditorModule>(FName(TEXT("LevelEditor")));
  + TSharedPtr<FTabManager> pTabManager = pLevelEditorModule ? pLevelEditorModule->GetLevelEditorTabManager() : FGlobalTabmanager::Get();
  + pTabManager->TryInvokeTab(FTabId(TEXT("CesiumIon")));
  }
  void CesiumPanel::uploadToIon()
  