Couple Review Step in Editorial Workflow to Approval of PR in Version Control System

**Is your feature request related to a problem? Please describe.**
We need to turn on branch protection for the main branch in our repository to reach security requirements, which means you need at least 1 reviewer to approve a Pull Request before merging can be done. It is cumbersome to have to move out of the CMS and into Azure DevOps to click an approve button, when all the other steps occur in the CMS.

**Describe the solution you'd like**
* An "approve" button as part of the editorial workflow review step (which also approves the PR in the VCS)
* Approving a "review-step" draft would move it into the ready column in the CMS.
* The publish button would complete the merge of the PR, and only be available to do if the draft has been reviewed and approved.

**Describe alternatives you've considered**
At the moment it seems like the editors would have to switch tools to go to Azure DevOps to approve the PR for the text they are reviewing. This works short-term for us, but we want to support a fully editorial workflow without our editors in the CMS ever having to enter Azure DevOps.