Add the ability to choose multiple contacts at the same time in "Add a relationship" in Chandler.

[KiDxS]

Is your feature request related to a problem? Please describe.
When adding social relationships in Chandler, you can select an existing contact. However, it only allows you to choose a contact one at a time. Which takes a lot of effort and time to add multiple relationships.

Describe the solution you'd like
We would like to select multiple contacts to add to the relationships simultaneously. So that users don't have to repeat the process many times to add relationships.

We may take advantage of this button since we already have this button.

Additional context