[core] Support exact type matches for type resolution from XPath

[jsotuyod]

As shown in #666 (comment)

It would be interesting to extend the current type resolution XPath functions to allow for exact matches (no inheritance).

Currently XPath can only use a typeof function that will check if the type of the given node is a descendant of a given type (same rules as instanceof). But sometimes we want to check if a type's class is explicitly a given one (usually getClass() == Something.class).