Bundle editorial workflow changes into one review branch

**- Do you want to request a *feature* or report a *bug*?**
Feature request

**- What is the current behavior?**
Currently every page updated or created within an editorial workflow setup gets applied as a separate pull request. The current workflow when hosting with Netlify is:

1. Single page edited or created within CMS.
2. Pull request created on Github to manage changes for that page.
3. Deploy automatically started on Netlify for that one change.
4. Deploy notification sent with URL showing just that one change.

**- What is the expected behavior?**
It would be great to have a way within the CMS to combine changes so that they can be reviewed together in context before going live. A new workflow could be:

1. On editorial workflow page, provide button that says "Review changes".
2. When button is clicked, the option to select individual changes to review via the cards can be presented.
3. A prompt is provided to label these changes.
4. When confirmed, a new branch is created using the label name, and all the pull requests selected via the cards will be merged into the new branch.
5. Deploy automatically started on Netlify for that new branch.
6. Deploy notification sent with URL showing all changes selected.

It would be good to maintain a list of branches created this way in the editorial page UI so that any further changes can be remerged into the same branch, or have the branch eventually merged with master and then delete the branch as well as close all related pull requests.