[Weblate] Replace msghack with podebug

Originally created by @hefee on #17375 (Redmine)

msghack was removed with translate-toolkit 1.1.0. In Debian this file is
still shipped inside the package. But let’s do not depdend on such
acient scripts. The replacement for `msghack —blank` is `podebug
—style=blank` as podebug detects the file format by filenamne suffix,
we need to create a temporaly file with a po suffix.

Feature Branch: https://salsa.debian.org/hefee/puppet-tails/:hefee/msghack_replacement