Currently, annotations are only shown on added or modified lines in a pull request.

This missed lots of use cases (e.g. unused imports).

This was split from BSERV-11472 where the use case was:

In particular, I can imagine making our build server validate hyperlinks between Markdown files and report any dangling references to Code Insights. Then, if someone deletes a file or anchor that is the target of a hyperlink, that will cause a Code Insights annotation on the hyperlink; but Bitbucket Server will not display this annotation because line containing the hyperlink was not modified.