If you had an image thumbnail for a file 'Foo?.png' on the page,
ve.ui.MWMediaContextItem and ve.ui.MWMediaDialog did not escape
the '?' when linking to it, which resulted in incorrect links.
Similarly, if you had an internal link to the page 'Foo?',
ve.ui.MWInternalLinkContextItem did not escape it.
Additionally, the links were always generated as if the wiki was
using short URLs, even when it is not (T233628).
The approach using mw.Title is copied from ve.ui.MWGalleryDialog.
Bug: T233628
Change-Id: I10256ed6883dae0ea216de4c0719f03d7fd19ae4