The display name, filter string, and tooltips for the property editor (and associated detail customizations) are now stored as FText rather than FString. This allows us to remove SLATE_TEXT_ARGUMENT from the detail customization widgets.
[CL 2372595 by Jamie Dale in Main branch]
#change Removed GGameName usage from code and replaced it with FApp::*GameName API
#change Added FApp::SetGameName(), FApp::IsGameNameEmpty()
#change Added IFileManager::GetFilenameOnDisk to get the correct case of a filename on disk
#change Renamed GGameName to GInternalGameName
[CL 2328446 by Robert Manuszewski in Main branch]