[feature]: Differentiate "duplicated by" from "duplicate of" relations

Is there an existing issue for this?

• I have searched the existing issues

Summary

Plane correctly differentiates "blocked by" and "blocking" relations between work items. However, for some reason I don't understand, "duplicate of" was made symmetrical. So there's no way to know which card is the duplicate of the other card.

The relation should be asymmetrical, like "blocked by".

If B is a duplicate of A and as a user you decide to keep A and close B as a duplicate, the expected behaviour would be:

• Mark B as a "duplicate of" A
• … Which automatically marks A as "duplicated by" B

Or the other way around (both must work):

• Mark A as "duplicated by" B
• … Which automatically marks B as "duplicate of" A.

Why should this be worked on?

When a card is a duplicate of another card, it's important to identify which card is the one that remains, and which one is the duplicate.