Add Ability to Schedule a Revision

[sjstark]

We had a need to schedule a draft, but then also schedule returning to the initial state. Unfortunately, something to do with the way Neo blocks function, we weren't able to create two drafts from the same point and schedule both (Draft 1 would write, and then the Draft 2 diffs would see the committed Draft 1 diffs as more up to date and would not implement Draft 2 changes)

We updated the publisher package to allow for scheduling a revision (including the current revision). Revisions are seen as an absolute truth and don't use a diff function to apply changes (like the issues we saw with scheduling drafts)

[lukasNo1]

Hey sjstark, it basically looks good, but i have some feedback

src/controllers/EntriesController.php:81 -> draft can be null at this point

src/templates/_cp/entriesEditRightPane.twig:54 -> the "creator" variable doesn't exist, which throws an exception

The "publishRevisionId" db field should be in a new migration and not in the Install.php, as the install migration only gets called on first plugin install