Show deprecation message on project milestone page for category tabs

What does this MR do?

This MR adds deprecation banner under Project Milestone page for the category tabs.

Screenshots

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [ ] Documentation created/updated
• [ ] Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• [ ] Conforms to the database guides

Closes #47943 (closed)