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/updates/utils.go

@@ -0,0 +1,87 @@
+package updates
+
+import (
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+func validatePts(pts, ptsCount int) error {
+	if pts < 0 {
+		return errors.Errorf("invalid pts value: %d", pts)
+	}
+
+	if ptsCount < 0 {
+		return errors.Errorf("invalid ptsCount value: %d", ptsCount)
+	}
+
+	return nil
+}
+
+func validateQts(qts int) error {
+	if qts < 0 {
+		return errors.Errorf("invalid qts value: %d", qts)
+	}
+
+	return nil
+}
+
+func validateSeq(seq, seqStart int) error {
+	if seq < 0 {
+		return errors.Errorf("invalid seq value: %d", seq)
+	}
+
+	if seqStart < 0 {
+		return errors.Errorf("invalid seqStart value: %d", seq)
+	}
+
+	return nil
+}
+
+func getDialogPts(dialog tg.DialogClass) (int, error) {
+	d, ok := dialog.(*tg.Dialog)
+	if !ok {
+		return 0, errors.Errorf("unexpected dialog type: %T", dialog)
+	}
+
+	pts, ok := d.GetPts()
+	if !ok {
+		return 0, errors.New("dialog has no pts field")
+	}
+
+	return pts, nil
+}
+
+func msgsToUpdates(msgs []tg.MessageClass, channel bool) []tg.UpdateClass {
+	updates := make([]tg.UpdateClass, 0, len(msgs))
+	for _, msg := range msgs {
+		if channel {
+			updates = append(updates, &tg.UpdateNewChannelMessage{
+				Message:  msg,
+				Pts:      -1,
+				PtsCount: -1,
+			})
+			continue
+		}
+
+		updates = append(updates, &tg.UpdateNewMessage{
+			Message:  msg,
+			Pts:      -1,
+			PtsCount: -1,
+		})
+	}
+
+	return updates
+}
+
+func encryptedMsgsToUpdates(msgs []tg.EncryptedMessageClass) []tg.UpdateClass {
+	updates := make([]tg.UpdateClass, 0, len(msgs))
+	for _, msg := range msgs {
+		updates = append(updates, &tg.UpdateNewEncryptedMessage{
+			Message: msg,
+			Qts:     -1,
+		})
+	}
+
+	return updates
+}