Draft: Add ability to duplicate a flow

What does this MR do and why?

Continuation of !203642 (merged), but this MR adds the duplicate button for flows

Screenshots or screen recordings

How to set up and validate locally

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #561515 (closed)