Because of the way Qt interprets the environment variable
LANG, using `sr@latin` or `sr@latn` or `ca@valencia` would
get you `sr` or `ca`, respectively, which isn't an exact
match. Now that Translation has special-handling for
those values of LANG, match with the ID first.
This allows starting Calamares in Serbian (Latin script)
or Catalan (Valencia) for locales that need it. (Qt doesn't
recognize ca@valencia as a variant, since that's a region-
based locale, not country- or script-based)
8aa8597ab0
