Add Previous and Next buttons to revision view

Problem/Motivation

Currently, in order to figure out which revision you might want to revert to, one has to do it from the list of revisions, for example, /node/1/revisions, then click around to the different revisions defined the one you want. You have to click into each revision from the list and see whether it has the content you want to revert to. This creates a cognitive load from having to remember which versions you've seen if you've previously looked through the revisions and not cleared your browser history before re-starting your process. It's also a lot of clicks. It would be much better if a user could page forward and back through the various revisions.

Steps to reproduce

On a website which automatically creates a new revision for each new draft of a page, while logged in as a user who has permission to revert:

1. Click Content, then Add Content, then Basic Page.
2. In the title field, type "Test reversion feature"
3. In the body field, type "This is the first revision."
4. Leave Published checked.
5. Click Save.
6. Click Edit.
7. Change "first" to "second".
8. Click Save.
9. Click Edit.
10. Change "second" to "third".
11. Click Save.
12. Click Edit.
13. Change "third" to "fourth".
14. Click Save.
15. Click Revisions.
16. Click the third revision in the list (the second revision from the bottom).

Desired result: If there is a previous revision, then there is a Previous button on the page which, when clicked, goes to the previous revision. If there is a next revision, then there is a Next button on the page which, when clicked, goes to the next revision.

Actual result: There is no Previous or Next button. I have to go back to the previous screen, remember which revision I chose previously, and choose the next revision that I want to look at. If I lose track, then I wind up skipping revisions or viewing a revision more than once.

Proposed resolution

Add Previous and Next buttons to /node/[node number]/revisions/[revision number]/view

Remaining tasks

User interface changes

Add Previous and Next buttons to /node/[node number]/revisions/[revision number]/view

API changes

Data model changes

Release notes snippet