kbdnames-maker: Call `{bind,}textdomain` after switching locale

There's a change in perl 5.28 to use `uselocale()` & friends instead of
gettext directly, to support thread safety. Apparently this causes the
results of `gettext()` calls to be cached now where they weren't before,
and this breaks our keyboard name generation. For example, we have

  en_GB*model*sun_type6_jp*Sun Type 6 (Japonesa)

instead of

  en_GB*model*sun_type6_jp*Sun Type 6 (Japanese)

and many many other examples.

Calling `bindtextdomain()` and then `textdomain()` after changing locale
causes the cache to be invalidated and we get correct results again.

LP: #1817453