fast-uri vulnerable to host confusion via failed IDN canonicalization

Impact fast-uri versions = 2.3.1, = 4.0.0 fail to canonicalize Unicode/IDN hostnames for HTTP-family URLs. The IDN conversion path calls URL.domainToASCII... on the global WHATWG URL constructor, where that helper does not exist. The resulting TypeError is silently routed into parsed.error, but...