Add support for gettext .po files

[jayvdb]

A filter for gettext .po files would allow verifying that the text in the input language was spelt correctly, thereby finding errors in the text of many other formats which extract text to .po files for translation.

There are Python libraries for .po files which can help, e.g. https://pypi.org/project/polib/

[facelessuser]

I think this would be a good idea. Whether this is something for the core project or a 3rd party plugin is another question. I do think it would be very helpful to some. I'd be interested to see if there was a spec on .po files. If this was done in the core, I'd hate to pull in another dependency. All we really want is to target the necessary strings polib. Granted, if complexity is high enough, using a dependency is needed. exposing an easy way to navigate HTML required us to pull in BeautifulSoup (and for me to write a better CSS selector library, but I digress).

On the one hand, I can see the appeal for something like a .po filter in the core. It is a common enough thing for anyone doing localization. On the other hand, it does create more default dependencies and a larger maintenance burden on the core, one I'd have to assume.

I'll consider it, but if we decide to do this, it may be a low priority. With that said, anyone can create a 3rd party plugin if it is needed.

@gir-bot remove S: triage @gir-bot add T: feature, S: maybe, S: needs-decision