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/internal/manager/handler.go

@@ -0,0 +1,26 @@
+package manager
+
+import (
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/mtproto"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+// Handler abstracts updates and session handler.
+type Handler interface {
+	OnSession(cfg tg.Config, s mtproto.Session) error
+	OnMessage(b *bin.Buffer) error
+}
+
+// NoopHandler is a noop handler.
+type NoopHandler struct{}
+
+// OnSession implements Handler.
+func (n NoopHandler) OnSession(cfg tg.Config, s mtproto.Session) error {
+	return nil
+}
+
+// OnMessage implements Handler
+func (n NoopHandler) OnMessage(b *bin.Buffer) error {
+	return nil
+}