Make external entities translatable

Adding ✨ Translation support in vertical data aggregation Active as related.

@rp7: Would you kindly let us know what's left to do here? Thanks.

Been using this on a quite busy project in production for a few months now, for 3 separate annotatable external entity types. No issues reported so far.

But it now appears to be in conflict with ✨ Translation support in vertical data aggregation Active , which is tailored to a different kind of external API format.

Besides that, test coverage is non-existent yet.

Thanks for the update!

Okay, so we need to figure out how to incorporate both approaches without collision.