Ability to mark comment as resolved

As reviewer

I want to comment a file or line and I would the developer to let me know if the comment has been considered and fixed

As developer

I want indicate to the reviewer that my changes is solving the comment by mark the it as resolved

 The desired comments (to fix) could be identified with an option, blocking the ability to merge if they are not fixed. When that kind of comment is added, a task could be created automatically (may the title could be truncate in the tasks list and link the associated comment)