Clone action for glossaries

Thanks for the issue. The glossary is buildt upon the possibilities of the API of deepL, that's why cannot create glossaries/ list that are independent from any source or target language.
More information can be found on their documentation: https://www.deepl.com/docs-api/translate-text/translate-text / https://www.deepl.com/docs-api/glossaries

We still need to create one glossary for each language pair to use it, while requesting the translation.

Cloning capabilities

For cloning glossary entities, you can use the entity_clone module.
Since glossary entities are normal content entities, those are supported out-of-the-box by the module.
https://www.drupal.org/project/entity_clone →