otDnssdQuerySubscribeCallback

Is called when a DNS-SD query subscribes one of: 1. a service name. 2. a service instance name. 3. a host name. The DNS-SD query implementation is responsible for identifying what @p aFullName is. If @p aFullName is a service name or service instance name, the DNS-SD query implementation should discover corresponding service instance information and notify the DNS-SD server using `otDnssdQueryHandleDiscoveredServiceInstance`. If @p aFullName is a host name, the DNS-SD query implementation should discover the host information and notify the DNS-SD server using `otDnssdQueryHandleDiscoveredHost`. @sa otDnssdQueryHandleDiscoveredServiceInstance @sa otDnssdQueryHandleDiscoveredHost