[Feature] Merge person properties when missing

The feature


Today, if you merge _person A_ into _person B_, _person A_ having a name and _person B_ having not one, _person A_'s name would be lost. It would be nice if properties that are missing on the destination person would be filled from the source person - with a proper notice to the user of course.

This can be prevented by reverting the merge (merge B into A), but maybe I'm already on _person A_'s page and that's faster, or maybe I bumped into the 500 people limit of the API so I can only see _person A_ and start the merge from there.

This is particularly relevant since the addition of date of birth in #3721 (date of birth follows the same principle as for the name).

Platform


• Server
• Web
• Mobile