http3: add compatibility with net/http.ResponseController (#3790)

* feat: compatibility with "net/http".ResponseController

* better deadline tests

* don't run deadline tests on Go 1.19

* skip deadline tests on Go 1.19

integrationtests/self/go120_test.go

@@ -0,0 +1,22 @@
+//go:build go1.20
+
+package self_test
+
+import (
+	"net/http"
+	"time"
+)
+
+var go120 = true
+
+func setReadDeadline(w http.ResponseWriter, deadline time.Time) error {
+	rc := http.NewResponseController(w)
+
+	return rc.SetReadDeadline(deadline)
+}
+
+func setWriteDeadline(w http.ResponseWriter, deadline time.Time) error {
+	rc := http.NewResponseController(w)
+
+	return rc.SetWriteDeadline(deadline)
+}