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/auth/qrlogin/errors.go

@@ -0,0 +1,23 @@
+package qrlogin
+
+import (
+	"fmt"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+// MigrationNeededError reports that Telegram requested DC migration to continue login.
+type MigrationNeededError struct {
+	MigrateTo *tg.AuthLoginTokenMigrateTo
+
+	// Tried indicates that the migration was attempted.
+	//
+	// Deprecated: do not use. QR login uses migrate function passed via
+	// options.
+	Tried bool
+}
+
+// Error implements error.
+func (m *MigrationNeededError) Error() string {
+	return fmt.Sprintf("migration to %d needed", m.MigrateTo.DCID)
+}