It Might be a specificity of our pull request process but I still have some request in case it makes sense on a more larger context.
For us it is the responsability of the reviewer to validate the pull request tasks and not the author. So for a clear way to know what status the task is in, as author and once the task is done we edit the task with a "*" which means that te task is "Done and to be checked by the reviewer".
The reviewer then needs to look for the tasks with a "*" and check them when they are effectively done.
Note that the author could check the task and the reviewer delete it, but we like to keep track of the process and this would not allow it. Whether leaving a comment without a task, which looks like an oversight or remove the comment altogether which would erase the pull request history.

In Short:
Right now there is no clear way to know whose turn it is to work on the PR: The reviewer or the author. And that is where the feature request comes.
You recently added the "request change" status on the PR from the reviewer side, we would like for the author to be able to change this status with a "change are done and can be reviewed again" clearly visible in the pull request list.

Side note:
A clear way to do the same on the pull request task would be also a great help, editing with a "*" is not really a nice and flowy process. A three status tasks would be very helpful: "to be done by author", "done by author need checking by reviewer", "checked by reviewer and validated"