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/peers/members/errors.go

@@ -0,0 +1,24 @@
+package members
+
+import (
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+// ChatInfoUnavailableError reports that chat members info is not available.
+type ChatInfoUnavailableError struct {
+	Info *tg.ChatParticipantsForbidden
+}
+
+// Error implements error.
+func (c *ChatInfoUnavailableError) Error() string {
+	return "chat members info is unavailable"
+}
+
+// ChannelInfoUnavailableError reports that channel members info is not available.
+type ChannelInfoUnavailableError struct {
+}
+
+// Error implements error.
+func (c *ChannelInfoUnavailableError) Error() string {
+	return "channel members info is unavailable"
+}