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/telegram/handle_updates_test.go

@@ -0,0 +1,40 @@
+package telegram
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+type mockHandler struct {
+	LastUpdate tg.UpdatesClass
+}
+
+func (m *mockHandler) Handle(ctx context.Context, u tg.UpdatesClass) error {
+	m.LastUpdate = u
+	return nil
+}
+
+func TestClient_processUpdates(t *testing.T) {
+	msg := &tg.Message{
+		ID: 1,
+	}
+	upd := &tg.Updates{
+		Updates: []tg.UpdateClass{&tg.UpdateNewMessage{
+			Message: msg,
+		}},
+	}
+
+	t.Run("Handle", func(t *testing.T) {
+		mock := &mockHandler{}
+		c := new(Client)
+		c.updateHandler = mock
+
+		err := c.processUpdates(upd)
+		require.NoError(t, err)
+		require.Equal(t, upd, mock.LastUpdate)
+	})
+}