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/proto/codec/intermediate_test.go

@@ -0,0 +1,45 @@
+package codec
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/go-faster/errors"
+	"github.com/stretchr/testify/require"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+)
+
+func TestIntermediate(t *testing.T) {
+	t.Run("Ok", func(t *testing.T) {
+		msg := bytes.Repeat([]byte{1, 2, 3}, 100)
+		buf := new(bytes.Buffer)
+		if err := writeIntermediate(buf, &bin.Buffer{Buf: msg}); err != nil {
+			t.Fatal(err)
+		}
+		var out bin.Buffer
+		if err := readIntermediate(buf, &out, false); err != nil {
+			t.Fatal(err)
+		}
+		require.Equal(t, msg, out.Buf)
+	})
+	t.Run("BigMessage", func(t *testing.T) {
+		codec := Intermediate{}
+		t.Run("Read", func(t *testing.T) {
+			var b bin.Buffer
+			b.PutInt(maxMessageSize + 10)
+
+			var out bin.Buffer
+			if err := codec.Read(&b, &out); !errors.Is(err, invalidMsgLenErr{}) {
+				t.Error(err)
+			}
+		})
+		t.Run("Write", func(t *testing.T) {
+			buf := make([]byte, maxMessageSize+10)
+
+			if err := codec.Write(nil, &bin.Buffer{Buf: buf}); !errors.Is(err, invalidMsgLenErr{}) {
+				t.Error(err)
+			}
+		})
+	})
+}