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/tgtest/middleware.go

@@ -0,0 +1,72 @@
+package tgtest
+
+import (
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+// UnpackInvoke is a simple Handler middleware to unpack some Invoke*-like requests.
+// Including:
+//
+//	tg.InvokeWithLayerRequest
+//	tg.InitConnectionRequest
+//	tg.InvokeWithoutUpdatesRequest
+func UnpackInvoke(next Handler) Handler {
+	return HandlerFunc(func(srv *Server, req *Request) error {
+		id, err := req.Buf.PeekID()
+		if err != nil {
+			return err
+		}
+
+		// TODO(tdakkota): handle more Invoke* requests.
+		var (
+			obj = peekIDObject{}
+			r   bin.Decoder
+		)
+		for {
+			switch id {
+			case tg.InvokeWithLayerRequestTypeID:
+				r = &tg.InvokeWithLayerRequest{
+					Query: &obj,
+				}
+				// TODO(tdakkota): pass Layer to session.
+			case tg.InitConnectionRequestTypeID:
+				r = &tg.InitConnectionRequest{
+					Query: &obj,
+				}
+				// TODO(tdakkota): pass DeviceInfo to session.
+			case tg.InvokeWithoutUpdatesRequestTypeID:
+				r = &tg.InvokeWithoutUpdatesRequest{
+					Query: &obj,
+				}
+				// TODO(tdakkota): pass NoUpdates flag to session.
+			default:
+				return next.OnMessage(srv, req)
+			}
+
+			if err := r.Decode(req.Buf); err != nil {
+				return err
+			}
+			id = obj.TypeID
+		}
+	})
+}
+
+type peekIDObject struct {
+	TypeID uint32
+}
+
+func (t *peekIDObject) Decode(b *bin.Buffer) error {
+	id, err := b.PeekID()
+	if err != nil {
+		return errors.Wrap(err, "peek id")
+	}
+	t.TypeID = id
+	return nil
+}
+
+func (t *peekIDObject) Encode(*bin.Buffer) error {
+	return errors.New("peekIDObject must not be encoded")
+}