Fix EZP-22735: Make {{ path( 'ez_urlalias' ) }} polymorphic

A fix for already existing issue at JIRA: https://jira.ez.no/browse/EZP-22735

Common usecase is to generate an URL to content in Relation field value.
Yeah, that's what I've been asking. Which one? `LogicException`? For example: `Cannot generate an UrlAlias route for content without main location`