Update incident header layout

What does this MR do and why?

This MR updates the incident header layout to match issues and epics. The issue and epic header layout was updated recenetly in !127613 (merged).

• Moves the header information from above the title to below the title
• Moves the close/open button and actions dropdown from the end of the header information to the end of the title

Changelog: changed

Issue: #414523 (closed)

Subsequent MRs will clean up unused code etc

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Create an incident then go to an incident to test the new header layout

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.