Resolve "Customize branch name when using create branch in an issue"
What does this MR do?
This MR adds an ability to type a custom branch name in the
Create merge request dropdown placed in an issue.
- Add backend specs
- Add frontend specs
Why was this MR needed?
It improves UX of branch management.
Screenshots (if relevant)
To be added.
Does this MR meet the acceptance criteria?
- Changelog entry added, if necessary
- Documentation created/updated
- API support added
- Tests added for this feature/bug
- Has been reviewed by UX
- Has been reviewed by Frontend
- Has been reviewed by Backend
- Has been reviewed by Database
- Conform by the merge request performance guides
- Conform by the style guides
- Squashed related commits together
What are the relevant issue numbers?
Closes #21143 (closed)