refactor(netx): extract tlsdialer from dialer

internal/engine/netx/tlsdialer/logging_test.go

@@ -0,0 +1,28 @@
+package tlsdialer_test
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"io"
+	"testing"
+
+	"github.com/apex/log"
+	"github.com/ooni/probe-cli/v3/internal/engine/netx/tlsdialer"
+)
+
+func TestLoggingTLSHandshakerFailure(t *testing.T) {
+	h := tlsdialer.LoggingTLSHandshaker{
+		TLSHandshaker: tlsdialer.EOFTLSHandshaker{},
+		Logger:        log.Log,
+	}
+	tlsconn, _, err := h.Handshake(context.Background(), tlsdialer.EOFConn{}, &tls.Config{
+		ServerName: "www.google.com",
+	})
+	if !errors.Is(err, io.EOF) {
+		t.Fatal("not the error we expected")
+	}
+	if tlsconn != nil {
+		t.Fatal("expected nil tlsconn here")
+	}
+}