Checks whether a string is a URL pointing at a different host than the current page.
Deprecated
Renamed to isExternalUrl (goldies/types/isExternalUrl), which works the same
way. isUrl will be removed in goldies 6.0. To check whether a string is any valid URL,
use the built-in URL.canParse(str).
Checks whether a string is a URL pointing at a different host than the current page.