move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/mtproxy/faketls/record_test.go

@@ -0,0 +1,24 @@
+package faketls
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRecord(t *testing.T) {
+	a := require.New(t)
+	r := record{
+		Type:    RecordTypeApplication,
+		Version: Version10Bytes,
+		Data:    []byte(`abcd`),
+	}
+	buf := bytes.NewBuffer(nil)
+
+	_, err := writeRecord(buf, r)
+	a.NoError(err)
+	r2, err := readRecord(buf)
+	a.NoError(err)
+	a.Equal(r, r2)
+}