Wikis: Combine pages with the same name as directories in trees
Release notes
Problem to solve
This is a follow-up to #17673 (closed).
If you have a wiki page and a directory with the same name on the same level, they will appear twice.
In this example the first "folder" links to a page, while the second "folder" is just static text for a directory:
Intended users
All wiki users.
User experience goal
The sidebar should not be confusing.
This also aligns more with other wiki engines, which often just have pages and nested pages.
Proposal
We should combine the page and directory into a single entry.
There's an edge case if two entries have the same name, but differ in casing. We should probably combine those as well, and probably prefer the page name.