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/transport/protocol_test.go

@@ -0,0 +1,39 @@
+package transport
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+)
+
+func TestProtocol_Pipe(t *testing.T) {
+	a := require.New(t)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	payload := []byte("abcdabcd")
+	test := func(c1, c2 Conn) {
+		go func() {
+			b1 := &bin.Buffer{Buf: payload}
+			a.NoError(c1.Send(ctx, b1))
+		}()
+
+		b2 := &bin.Buffer{}
+		a.NoError(c2.Recv(ctx, b2))
+		a.Equal(payload, b2.Buf)
+	}
+
+	c1, c2 := Intermediate.Pipe()
+	defer func() {
+		a.NoError(c1.Close())
+		a.NoError(c2.Close())
+	}()
+
+	test(c1, c2)
+	test(c2, c1)
+}