Looking at https://en.wikipedia.org/w/index.php?title=Special:Cite&page=%C4%B0stanb... you see a lot of unpretty URLs (Bug 7329 [0]).
With https://gerrit.wikimedia.org/r/#change,3897 a new global function wfExpandIRI() was introduced for printer friendly URLs in unicode.
First and easiest solution for pretty URLs would be to run the function which outputs {{canonicalurl:}} through wfExpandIRI().
Is this safe? Are all browsers able to handle IRIs [1]?
Otherwise I am thinking about creating a new magic word {{canonicaliri:}}. This can be used in [2] for example.
Raimond.
[0] https://bugzilla.wikimedia.org/show_bug.cgi?id=7329 [1] https://en.wikipedia.org/wiki/Internationalized_Resource_Identifier [2] https://en.wikipedia.org/wiki/MediaWiki:Cite_text