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/proto/rpc_result.go

@@ -0,0 +1,41 @@
+package proto
+
+import (
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+)
+
+// ResultTypeID is TL type id of Result.
+const ResultTypeID = 0xf35c6d01
+
+// Result is rpc_result#f35c6d01.
+type Result struct {
+	RequestMessageID int64
+	Result           []byte
+}
+
+// Encode implements bin.Encoder.
+func (r *Result) Encode(b *bin.Buffer) error {
+	b.PutID(ResultTypeID)
+	b.PutLong(r.RequestMessageID)
+	b.Put(r.Result)
+	return nil
+}
+
+// Decode implements bin.Decoder.
+func (r *Result) Decode(b *bin.Buffer) error {
+	if err := b.ConsumeID(ResultTypeID); err != nil {
+		return err
+	}
+	{
+		v, err := b.Long()
+		if err != nil {
+			return err
+		}
+		r.RequestMessageID = v
+	}
+
+	r.Result = append(r.Result[:0], b.Buf...)
+	b.Skip(len(b.Buf))
+
+	return nil
+}