[wiki] List all wiki pages

[Mjokfox]

I think mentioned like this in #1423, simply a wiki page that lists all existing pages

[shish]

Could this be wiki:all rather than all, to keep it in line with the other "special" pages like wiki:sidebar and wiki:default?

Also maybe worth adding a link to the new page on onPageSubNavBuilding() so that people know it exists 👀 (Though I'm not sure what label I'd give it, maybe "Pages" or "Page List" or something?)

[shish]

Excellent :D Thank you ^_^