Add API support for wiki pages
What does this MR do?
This MR adds API endpoints for:
- Getting a list of wiki pages.
- Getting a wiki page.
- Creating a wiki page.
- Editing/updating a wiki page.
- Deleting a wiki page.
Are there points in the code the reviewer needs to double check?
- Documentation wording.
- Complexity of specs.
Why was this MR needed?
It improves our API.
Does this MR meet the acceptance criteria?
- Changelog entry added, if necessary
- Documentation created/updated
- API support added
- Added for this feature/bug
- All builds are passing
- Has been reviewed by UX
- Has been reviewed by Frontend
- Has been reviewed by Backend
- Has been reviewed by Database
- Conform by the merge request performance guides
- Conform by the style guides
Branch has no merge conflicts with
master(if it does - rebase it please)
- Squashed related commits together
What are the relevant issue numbers?
Closes #12747 (closed)