Re-order list of resolvers according to their searchOrder (netty#11236)

Motivation:
Mac OS specific DNS resolver fails to take into account search order
of resolvers causing wrong resolver being used is some circumstances

Modifications:
Re-order array of resolvers using their sort order as an ordering key.
Final order is opposite of the search order to make sure that resolver
with the lower sort order goes last (so it overrides previous one
in the `resolverMap`).

Result:
Fixes issue netty#11225

resolver-dns-native-macos/src/main/java/io/netty/resolver/dns/macos/MacOSDnsServerAddressStreamProvider.java

@@ -29,7 +29,9 @@
 import io.netty.util.internal.logging.InternalLoggerFactory;
 
 import java.net.InetSocketAddress;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
@@ -43,6 +45,16 @@
  */
 public final class MacOSDnsServerAddressStreamProvider implements DnsServerAddressStreamProvider {
 
+    private static final Comparator<DnsResolver> RESOLVER_COMPARATOR =
+            new Comparator<DnsResolver>() {
+                @Override
+                public int compare(DnsResolver r1, DnsResolver r2) {
+                    // Note: order is descending (from higher to lower) so entries with lower search order override
+                    // entries with higher search order.
+                    return r1.searchOrder() < r2.searchOrder() ? 1 : (r1.searchOrder() == r2.searchOrder() ? 0 : -1);
+                }
+            };
+
     private static final Throwable UNAVAILABILITY_CAUSE;
 
     private static final InternalLogger logger =
@@ -120,6 +132,7 @@ private static Map<String, DnsServerAddresses> retrieveCurrentMappings() {
         if (resolvers == null || resolvers.length == 0) {
             return Collections.emptyMap();
         }
+        Arrays.sort(resolvers, RESOLVER_COMPARATOR);
         Map<String, DnsServerAddresses> resolverMap = new HashMap<String, DnsServerAddresses>(resolvers.length);
         for (DnsResolver resolver: resolvers) {
             // Skip mdns