feat: tlsmiddlebox experiment (#817)

See https://github.com/ooni/probe/issues/2124

internal/engine/experiment/tlsmiddlebox/connect.go

@@ -0,0 +1,27 @@
+package tlsmiddlebox
+
+//
+// TCP Connect for tlsmiddlebox
+//
+
+import (
+	"context"
+	"time"
+
+	"github.com/ooni/probe-cli/v3/internal/measurexlite"
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+// TCPConnect performs a TCP connect to filter working addresses
+func (m *Measurer) TCPConnect(ctx context.Context, index int64, zeroTime time.Time,
+	logger model.Logger, address string, tk *TestKeys) error {
+	trace := measurexlite.NewTrace(index, zeroTime)
+	dialer := trace.NewDialerWithoutResolver(logger)
+	ol := measurexlite.NewOperationLogger(logger, "TCPConnect #%d %s", index, address)
+	conn, err := dialer.DialContext(ctx, "tcp", address)
+	ol.Stop(err)
+	measurexlite.MaybeClose(conn)
+	tcpEvents := trace.TCPConnects()
+	tk.addTCPConnect(tcpEvents)
+	return err
+}