Make sure hst:link also returns correct inclusion or exclusion of contextPath even if there is *no* HstRequestContext

When the HST request processing is skipped, still try to match the hostname to a virtualhost and set this on the request.

Usecase:

Developers should use hst:link tag in something like a login.jsp or error404,jsp page, that do not have an HstRequestContext at all. The hst:link tag must be used to include correct handling of including or excluding the contextPath in the url (httpd can strip it off).

The hst:link tag for path="..." must thus also work without HstRequestContext. It should then inspect the HttpServletRequest whether there is a VirtualHost matched. If so, then only include the contextPath if isContextPathInUrl returns true. If there is no virtualhost matched, we use the default isContextPathInUrl from the VirtualHosts (the host container)