refs #10438, refs #10106
* Renamed existing pages ctrl
* Splitted posts & pages for Admin API v2
* Added pages JSON input schema for Admin API v2
* Removed single author for Content & Admin API v2
- single author is not documented
- single author usage is deprecated in v0.1
- single author usage is removed in API v2
* Splitted posts & postsPublic controller for v2
* Removed requirement to send `status=all` from Admin API v2
* Removed `status` option from pages Content API v2
* Removed `status` options from Users Admin API v2
closes#10029
- allowed page option for users, posts, & tags browse
- The page query param was not forwarding to the query, meaning that when the admin client requested the next page of users or posts, it would receive the first page again.
