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/handle_session_created.go

@@ -0,0 +1,40 @@
+package mtproto
+
+import (
+	"github.com/go-faster/errors"
+	"go.uber.org/zap"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/mt"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/proto"
+)
+
+func (c *Conn) handleSessionCreated(b *bin.Buffer) error {
+	var s mt.NewSessionCreated
+	if err := s.Decode(b); err != nil {
+		return errors.Wrap(err, "decode")
+	}
+	c.gotSession.Signal()
+
+	created := proto.MessageID(s.FirstMsgID).Time()
+	now := c.clock.Now()
+	c.log.Debug("Session created",
+		zap.Int64("unique_id", s.UniqueID),
+		zap.Int64("first_msg_id", s.FirstMsgID),
+		zap.Time("first_msg_time", created.Local()),
+	)
+
+	if (created.Before(now) && now.Sub(created) > maxPast) || created.Sub(now) > maxFuture {
+		c.log.Warn("Local clock needs synchronization",
+			zap.Time("first_msg_time", created),
+			zap.Time("local", now),
+			zap.Duration("time_difference", now.Sub(created)),
+		)
+	}
+
+	c.storeSalt(s.ServerSalt)
+	if err := c.handler.OnSession(c.session()); err != nil {
+		return errors.Wrap(err, "handler.OnSession")
+	}
+	return nil
+}