RUN AS-IF-FOSS: Add canonical links for moved/duplicated/promoted issues

What does this MR do?

Duplicated/closed/promoted issues often appear first in Google search results, because they are older, but are out of date. This helps by making it so there's a canonical link to the current issue. This will ensure that the most relevant issue shows up in Google search results.

This adds a canonical link to any moved or duplicated issue's header that points to the issue that it was moved or duplicated to. To test, simply move an issue and see the new header value appear. No other issues should be changed.

Closes #222473 (closed)

Screenshots

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
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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