Network prefs: remove compile-time german localization

There are better way to achieve this, now.
Netprefs: Remove "/dev/net/" from displayed interface names

The name overlaps the status string when it's too long, so keep it
shorter.
Network prefs: update on tab switch

The rightmost part of the UI actually depends on which tab is selected
on the leftside. Intercept the tab change in the Show method, and
display the correct data.

Fixes #11400.