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/session.go

@@ -0,0 +1,24 @@
+package tgtest
+
+import (
+	"encoding/hex"
+
+	"go.uber.org/zap/zapcore"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/crypto"
+)
+
+// Session represents connection session.
+type Session struct {
+	// ID is a Session ID.
+	ID int64
+	// AuthKey is an attached key.
+	AuthKey crypto.AuthKey
+}
+
+// MarshalLogObject implements zap.ObjectMarshaler.
+func (s Session) MarshalLogObject(encoder zapcore.ObjectEncoder) error {
+	encoder.AddInt64("session_id", s.ID)
+	encoder.AddString("key_id", hex.EncodeToString(s.AuthKey.ID[:]))
+	return nil
+}