Improve local DNS server on darwin

We mistakenly believed that `libresolv`'s `search` function worked correctly in NetworkExtension, but it seems only `getaddrinfo` does.

This commit changes the behavior of the `local` DNS server in NetworkExtension to prefer DHCP, falling back to `getaddrinfo` if DHCP servers are unavailable.

It's worth noting that `prefer_go` does not disable DHCP since it respects Dial Fields, but `getaddrinfo` does the opposite. The new behavior only applies to NetworkExtension, not to all scenarios (primarily command-line binaries) as it did previously.

In addition, this commit also improves the DHCP DNS server to use the same robust query logic as `local`.

box.go

@@ -323,13 +323,14 @@ func New(options Options) (*Box, error) {
 			option.DirectOutboundOptions{},
 		)
 	})
-	dnsTransportManager.Initialize(common.Must1(
-		local.NewTransport(
+	dnsTransportManager.Initialize(func() (adapter.DNSTransport, error) {
+		return local.NewTransport(
 			ctx,
 			logFactory.NewLogger("dns/local"),
 			"local",
 			option.LocalDNSServerOptions{},
-		)))
+		)
+	})
 	if platformInterface != nil {
 		err = platformInterface.Initialize(networkManager)
 		if err != nil {