Merge a stricter version of check_po whose expectations are realistic into our master branch
_Originally created by @intrigeri on [#16328 (Redmine)](https://public-redmine-archive.tails.boum.org/code/issues/16328)_
It’s not clear if we really need tails/tails#15362 nor whether it’s 100%
realistic. So as a first step, before we can do tails/sysadmin#15082, let’s merge the
new version of this script, after reviewing its requirements, and
disabling the new checks that cannot be easily satisfied at the moment:
for example, checks that would not pass on PO files generated by current
ikiwiki shall be disabled, at least for now.
Feature Branch: tails.git:translation_platform_hooks
Parent Task: tails/tails#15079
### Related issues
- **Related to** tails/tails#16102
- **Related to** tails/tails#15819
- **Blocks** tails/sysadmin#15082
- **Blocks** tails/tails#15362
issue