IsRefToGateway returns whether the provided parent ref is a reference to a Gateway with the given namespace/name, irrespective of whether a section/listener name has been specified (i.e.

IsValidHostname validates that a given hostname is syntactically valid.

ValidateListeners validates protocols, ports and hostnames on a set of listeners.

ContourHTTPSProtocolType is the protocol for an HTTPS Listener that is to be used with HTTPProxy/Ingress, where the TLS details are provided on the HTTPProxy/Ingress rather than on the Listener.