Comments panel - comment appears twice

[lszomoru]

Testing microsoft/vscode#143545

1. Open a file from the pull request in the diff editor
2. Add a comment for the file

Comment appears twice in the comments panel.
It looks like the comment is added both to the file, as well as the "read only" resource.

[alexr00]

This has to do with how we handle comments from the "Pull Requests" view and the "Changes in Pull Request" view. Not a new issue, so I will fix for March.