Code tag styling for search term

What does this MR do?

This MR is part of the "Beautifying our UI" Epic. &989 (closed) as a fix to the following issue #30666 (closed)

This MR changes the styling of how the search term is displayed at the top of the search results. Instead of being plainly wrapped in quotes, it is now wrapped inside a <code> tag.

Screenshots

Before

After

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Fixes #30666 (closed)