Feature Request: Enhance choose merge request to filter out reviews approved by a user

[sankargorthi]

Feature Description

Gitlab's API supports

https://gitlab.yourdomain.com/dashboard/merge_requests?scope=all&state=opened&reviewer_username=user.name&not[approved_by_usernames][]=user.name

Allowing the opts to construct a URL with the not param would be quite useful

[sankargorthi]

I can look into contributing this. Looks like a fun addition.