Quick action to copy epics with no child epics/issues

Problem to solve

Currently a user has to create a new epic from scratch every time, even if it closely resembles one or more they already have.

Intended users

All users of epics that have permission to create new epics in a group.

Further details

This represents an initial implementation of #9398 (closed) for simple epics that have no child epics or issues. In effect this allows a user to use an epic as a template.

Proposal

A new quick action called /clone can be used to create a new epic with the attributes of the current one.

Syntax should align with that of the the proposed quick action for cloning issues #9421 (comment 135146293).

Permissions and Security

Usage should be restricted to users who have permission to create epics within the same group.

Documentation

Testing

Requires additional tests to the current suite of quick action and epic tests.

What does success look like, and how can we measure that?

An authorized user can create a new epic by cloning an existing one with a quick action.

What is the type of buyer?

Links / references