[Design] Merge details layout enhancements
## Proposal
Highlight key information from the merge details that is currently in the merge check widget.
- :art: [Figma](https://www.figma.com/design/JvdECCgXS5UF1Llll5AHX3/Merge-request-widgets?node-id=930-81873&t=AitKqhF23Vw2DO0X-1)
#### Goal
1. When landing the merge request page, users should know what the "state" of the merge request is without scrolling
- Currently users will need to scroll and find the merge widget on the page to read the status
#### Mock up
| Current | Proposal |
| ------ | ------ |
|  |  |
There are other states not illustrated here such as `merged` and `closed`. They will come once we refine the layout.
## Questions to answer
1. `@francoisrose` Do you imagine the Work Items line would also be shown if there aren't any linked issues? For me, it's often just as valuable to know at a glance that there isn't anything linked.
issue