Allow to filter by PR reviewer

[otbutz]

Description

We can already filter by assignee but it would be nice if we could filter by reviewer of a PR.

Benefits:

• check which PRs you reviewed (Type->Reviewed by you)
• check which PRs other users reviewed (Reviewer dropdown)

[6543]

nice idear - similar to #9408 (#9432)

only one thing: at some point we need a new UI to filter stuff since it would overload the UI

[stale]

This issue has been automatically marked as stale because it has not had recent activity. I am here to help clear issues left open even if solved or waiting for more insight. This issue will be closed if no further activity occurs during the next 2 weeks. If the issue is still valid just add a comment to keep it alive. Thank you for your contributions.

[otbutz]

Ping

[iarepandemonium]

This would be a really helpful function on my own projects too.

[slavus]

👍