Allow comments on lines that haven't changed

[saw-lau]

Issue description

Currently comments (or tasks) can be associated with changed lines or at the file level. Some people in my team would also like to be able to comment on unchanged lines in files that end up in the PR.

Feature Request

Problem to be solved

When performing a review, sometimes reviewers will notice errors or typos or something that they would like clarification on in lines that haven't changed between revisions, and currently they're unable to comment on these lines directly.

Proposed solution

Allow comments or tasks to be added to any line in files of the PR.

[pfeuffer]

Hi @saw-lau , thanks for this suggestion. It took me a while to remember, why we hadn't implemented this right away (it's not that far-fetched, is it?). It just makes the logic to display these comments a little bit harder, since you have to fetch these "out-of-diff" lines on an extra step to display these comments. It may not be much, but it's not nothing. We will see what we can do.