[L10n] Integrate translation platform

[Korb]

Problem / Use Case

Glossaries, translation consistency for segments/strings across languages, partial translation updates without having to search for differences or retranslate everything, length and punctuation checks—these are just a few examples of the benefits offered by specialized localization tools.

Proposed Solution

1. Weblate (open-source, self-hostable)

Proprietary, but free for FOSS projects:

3. Crowdin
4. Transifex
5. Lokalise (all three services are )

Related Issues

#79, #137, #149, #228, #263, #319, #329 and #345