MR Review: Respond to a diff thread

Problem to solve

The extension shows us comment threads on the diff, but doesn't allow us to comment in the thread. This issue is to enable and implement responses to diff threads.

Proposal

1. Enable responses
2. Extend the createNote method to return notes (with positions), instead of void
3. Implement reply() function on the gitlab_comment_thread
4. Add a Create comment now command and add it to the comments/commentThread/context menu

Further details

Example:

respond-example

This feature is implemented (not production-ready at all) in the POC (#293 (closed)) branch 293-new-comments-poc

Links / references