mdns: Allow resolve its own non-strict answers

the mDNS responder should not repeat questions when replying, however resolvers
must ignore these questions field if they are present. esp-idf mDNS
library does include questions in answering packets (thus not strictly
following the RFC6762) so the resolver did not correctly resolved
another instance host name.

Closes #6190

components/mdns/mdns.c

@@ -2753,7 +2753,7 @@ void mdns_parse_packet(mdns_rx_packet_t * packet)
         }
     }
 
-    if (header.questions && !parsed_packet->questions && !parsed_packet->discovery) {
+    if (header.questions && !parsed_packet->questions && !parsed_packet->discovery && !header.answers) {
         goto clear_rx_packet;
     } else if (header.answers || header.servers || header.additional) {
         uint16_t recordIndex = 0;
@@ -2796,13 +2796,14 @@ void mdns_parse_packet(mdns_rx_packet_t * packet)
 
             if (parsed_packet->discovery && _mdns_name_is_discovery(name, type)) {
                 discovery = true;
-            } else if (!name->sub && _mdns_name_is_ours(name)) {
-                ours = true;
-                if (name->service && name->service[0] && name->proto && name->proto[0]) {
-                    service = _mdns_get_service_item(name->service, name->proto);
-                }
             } else {
-                if (header.questions || !parsed_packet->authoritative || record_type == MDNS_NS) {
+                if (!name->sub && _mdns_name_is_ours(name)) {
+                    ours = true;
+                    if (name->service && name->service[0] && name->proto && name->proto[0]) {
+                        service = _mdns_get_service_item(name->service, name->proto);
+                    }
+                }
+                if (!parsed_packet->authoritative || record_type == MDNS_NS) {
                     //skip this record
                     continue;
                 }