UI polish on the webhook log page

What does this MR do and why?

This MR updates the Webhook Request Details page with some minor UI polish and page restructuring.

Screenshots or screen recordings

Project-level

Before	After

Admin-level

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

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 #335128 (closed)