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/codec/no_header.go

@@ -0,0 +1,18 @@
+package codec
+
+import "io"
+
+// NoHeader wraps codec to skip WriteHeader.
+type NoHeader struct {
+	Codec
+}
+
+// WriteHeader implements Codec.
+func (NoHeader) WriteHeader(io.Writer) error {
+	return nil
+}
+
+// ReadHeader implements Codec.
+func (NoHeader) ReadHeader(io.Reader) error {
+	return nil
+}