Add helpful info to MR sidebar
## Description
Often, I'm reading through the depths of an MR and then decide I want to checkout the branch. To do this, I have to scroll up to the top to get the branch name, which causes me to lose my place in the comments :disappointed:.
Is there a cool place in the sidebar where we could add the branch name (and potentially other helpful info)?
## What info could be potentially helpful?
- Source branch (and if on fork, the "Check out branch" button is really helpful)
- Target branch
- Commit ID
- Pipeline status
- Related issue
- Related MR
## Why is this helpful?
This information is commonly used for reviewing / understanding a MR. It'd be really nice if they were always visible so that I don't lose track of my position in the body.
issue