Ability to filter entries which have a saved draft

[rishifter]

We are working with a client on a project with a large number of entries (expected to be >70k). They have a publishing workflow where a team of authors are creating drafts for entries, which are then reviewed and published by a separate team of editors.

We've been unable to figure out a simple way to filter the entries which have a saved draft (and therefore need to be reviewed). The only way to see this in the list of entries in the CMS right now is to enable the Drafts column.

A filter which allowed filtering entries with/without drafts, and additionally for draft attributes like Created by or Edited by would be immensely useful to have.