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/mtproto/connect_test.go

@@ -0,0 +1,74 @@
+package mtproto
+
+import (
+	"context"
+	"crypto/rand"
+	"io"
+	"testing"
+	"testing/iotest"
+
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/clock"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/crypto"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/transport"
+)
+
+type closeConn struct {
+	closed bool
+}
+
+func (c *closeConn) Send(ctx context.Context, b *bin.Buffer) error {
+	return io.EOF
+}
+
+func (c *closeConn) Recv(ctx context.Context, b *bin.Buffer) error {
+	return io.EOF
+}
+
+func (c *closeConn) Close() error {
+	c.closed = true
+	return nil
+}
+
+func TestConn_connect(t *testing.T) {
+	t.Run("EnsureClose", func(t *testing.T) {
+		t.Run("Exchange", func(t *testing.T) {
+			a := require.New(t)
+
+			closeMe := &closeConn{}
+			c := Conn{
+				dialer: func(ctx context.Context) (transport.Conn, error) {
+					return closeMe, nil
+				},
+				clock: clock.System,
+				rand:  rand.Reader,
+				log:   zap.NewNop(),
+			}
+
+			a.Error(c.connect(context.Background()))
+			a.True(closeMe.closed)
+		})
+		t.Run("SessionID", func(t *testing.T) {
+			a := require.New(t)
+
+			closeMe := &closeConn{}
+			c := Conn{
+				dialer: func(ctx context.Context) (transport.Conn, error) {
+					return closeMe, nil
+				},
+				clock: clock.System,
+				authKey: crypto.AuthKey{
+					ID: [8]byte{1}, // Skip exchange.
+				},
+				rand: iotest.ErrReader(io.EOF),
+				log:  zap.NewNop(),
+			}
+
+			a.Error(c.connect(context.Background()))
+			a.True(closeMe.closed)
+		})
+	})
+}