EditPage: Wrap the pipe between "Cancel" and "Editing help" links in a <span>

This will make it possible to hide or style it without nasty hacks
like the one Vector extension's ext.vector.footerCleanup module uses.

Bug: 43689
Change-Id: Id9269876939d3453c53473f7e3650c375f6fdd22
Merge "EditPage: Wrap the pipe between "Cancel" and "Editing help" links in a <span>"