Generate and upload the product POT file to allow translating the product descriptions

[lslezak]

Problem

• The product descriptions in the ./products.d/*.yaml files are not translated
• That looks bad as those texts are quite long and displayed in the very first Agama dialog

Solution

• Extract the description texts from the YAML files
• Upload them to the agama-weblate repository

Testing

• Tested manually
• Example GitHub Action run
• Uploaded POT file

TODO

• Set up a new Weblate translation project so the translators can actually translate the texts
• Implement merging the translations back to the original YAML files
• Use the translations in the backend/frontend
• Document the product translations (if somebody wants to define own product)

[coveralls]

coverage: 75.063%. remained the same
when pulling b459244 on lslezak:master
into f1a8318 on openSUSE:master.

[imobachgs]

LGTM. It might be interesting to document this further just in case someone is interested on creating its own product.