feat(oohelperd): follow (and record) TH and probe endpoints (#890)

This diff introduces the following `oohelperd` enhancements:

1. measure both IP addresses resolved by the TH and IP addresses resolved by the probe;

2. when the URL scheme is http and there's no explicit port, measure both 80 and 443 (which will pay off big once we introduce support for optionally performing TLS handshakes);

3. include information about the probe and TH IP addresses into the results: who resolved each IP address, whether an address is a bogon, the ASN associated to an address.

This diff is part of https://github.com/ooni/probe/issues/2237

internal/cmd/oohelperd/main_test.go

@@ -14,7 +14,7 @@ import (
 	"github.com/ooni/probe-cli/v3/internal/runtimex"
 )
 
-func TestWorkAsIntended(t *testing.T) {
+func TestMainWorkingAsIntended(t *testing.T) {
 	// let the kernel pick a random free port
 	*endpoint = "127.0.0.1:0"