Translations with longer tab titles may cause tabs to disappear from the options menu

Currently if any translation were to use longer titles for any tab of the in-game options menu, it may cause one or more tabs to disappear. The german localization, for example, is near the limit and (as a demonstration) the addition of 3 underscores causes the Grafik tab to disappear. It is not possible to add a new tab in this situation, no matter how short its name.

I do not believe this issue is affects any existing localizations in OpenMW. However, in OpenMW-VR I add a fifth tab in the options menu specific to VR features. This causes both the VR and Grafik tabs to disappear. I'm opening this issue upstream as I believe this issue is best solved upstream, as I do not want VR to have unnecessarily divergent MyGUI layouts. It would also be useful for OpenMW if OpenMW ever wants to add more tabs.