Add breaking change warning to Docs UI

What does this MR do and why?

This MR adds a visual indicator to the Deprecations and Removals pages to notify the user if the item will result in a breaking change upon removal.

• View app

Follow-up Tasks

• Verify breaking_change values with PMs

Screenshots or screen recordings

How to set up and validate locally

1. Checkout this branch in a gitlab project within gitlab-development-kit
2. Serve the gitlab-docs project from within the same gitlab-development-kit
3. Visit http://127.0.0.1:3000/ee/update/deprecations.html -->

Related to

• gitlab-com/www-gitlab-com#12760 (closed)

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.