As a superuser, I want to be able to merge person-to-person relationship types to streamline the data entry process.

[kseniaryzhova]

Is your feature request related to a problem? Please describe.
There's a way to create new person-to-person relationship types but no way to merge them. We forsee a point where we identify a bunch of new relationship types and then find a way to streamline the categorization.

Describe the solution you'd like
I want to be able to merge person-to-person relationship types in the admin and retain all the existing data (just under a new name).