Improve the display of very long names in the user menu

While it was happening earlier, MDL-54559 testing discovered that, now, the problem is (2 points) worse. Everything there (name & icon) seem to be wrapping, causing the icon to fall out from the navigation bar

Instead, the icon should retain its position and only the name be wrapped / shortened ...

So, this issue is about to discuss and consider how those long names should be displayed together with the icon in the best possible way.

I'd consider this a bug and apply it to all supported branches if the solution is ok for that (safe, without dependencies...). It's a small detail, but a persistent and important one, IMO.

That's all, ciao