As a plugin developer I want to be bale to update the translation files and also update the MANIFEST.toml from translation files.

Picard has an helper script extract_plugin_translations.py. Also there is https://gist.github.com/rdswift/efa8da2acf88ee1f5885e2ad267e83ef .

As picard-cli already provides development commands we should also integrate the translation management there, so every plugin developer has easy access to it (e.g. by installing picard via pypi).