Add system notes when moving issues between epics
What does this MR do?
It adds system notes when an issue is moved from one epic to another
- System note inside the issue that is transferred:
Victor Wu @victorwu changed epic to &1234 6 days ago
- System note inside the epic that lost the issue:
Victor Wu @victorwu moved issue #1234 to epic &1234 6 days ago
- System note inside the epic that gained the issue:
Victor Wu @victorwu added issue #1234 from epic &1234 6 days ago
Are there points in the code the reviewer needs to double check?
Why was this MR needed?
Screenshots (if relevant)
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
- Internationalization required/considered
- If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan
What are the relevant issue numbers?
Closes #4261 (closed)