A job stored its error and its result's warning as English text, much
of it built with the values in it (volume paths, a disk, libvirt's
error), so no catalog could translate it, and the job pages and panel
showed English whatever the language.
A job now stores them as messages: our English text, marked for
translation, and its values; libvirt's own text is a message without
values and is shown as it is. The jobs API and pages put them in the
reader's language. OperationError keeps its text and values apart for
the same reason, so a refusal raised while a job is submitted is shown
translated too. Messages one after another still read as sentences.
Errors stored before are kept as one message each, shown as they were.
The VM page's and the Settings page's views marked their messages with
gettext_noop, so every message they gave (a refused resize, a saved
setting, a QoS change, a busy VM) showed in English whatever the
language, though the catalogs translate them. They translate in the
request's language now; their module-level texts lazily. The Settings
page's group titles stay English in the view, as the page links them
by their slugs and translates them itself.
Two values went into translated messages as English codes: a job's
state ("... is running on this resource") and a QoS direction ("Remove
the inbound limit ..."). They are named as the pages name them.
