Display branch rule details

What does this MR do and why?

Display branch rules details.

This is part of a bigger effort to Display branch rules details

MR breakdown

Description	MR
Restructure branch rules components	!98307 (merged)
Create view branch rules component	!98310 (merged)
Create branch protection component	!98970 (merged)
Display branch rule details	👈 this MR
Display Approvals and Status checks sections	follow-up
Display x matching branches link for wildcards	follow-up

(no changelog added because changes are behind a feature flag)

Screenshots

Testing

1. Enable the branch_rules feature flag
2. Setup a protected branch
3. Navigate to <project>/-/settings/repository#branch-rules
4. Click on Details next to the protected branch you created in step 1
5. The Branch rule details page should be loaded

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.

Related to #372362 (closed)