Feature/6299 new doc

* New doc struct for encryption keys https://leap.se/code/issues/6299
* Multi uid support https://leap.se/code/issues/6212
* Keep old key after upgrade https://leap.se/code/issues/6262

You are right the rise is missing. We use long key_ids everywhere, if there is two keys with the same key_id we have a serious problem, basically we found a security issue on OpenPGP. This is why I use logger.critial for that.

But you are right that is better to delete the key anyway, I'm fixing that.