thinking if we add byte and others into message.proto to increase the vaules supported type

[WeiTing1991]

currently byte strings are serialized as base64 encoded strings. we could make the support more robust by using the native bytes representation of protobuf.

[WeiTing1991]

NOTE: https://protobuf.dev/reference/protobuf/google.protobuf/#bytes-value
e.g.

message AnyData {
  oneof data {
    google.protobuf.Any message = 1;
    google.protobuf.Value value = 2;
    google.protobuf.BytesValue bytes =3;
    FallbackData fallback = 4;
  }
}

[WeiTing1991]

There's no bytes field in the AnyData oneof. Since the "base64:" prefix string convention is fragile
Bytes are still going through google.protobuf.Value.string_value with a "base64:" prefix (line 58 in core.py)

Some idea To fix it :

1. Add bytes bytes_value = 8; to the AnyData oneof in the proto
2. Change primitive_to_pb to use data_offset.bytes_value = obj instead of the base64 encoding
3. Change primitive_from_pb to handle the new bytes_value field
4. Keep the old base64 string path for backward compatibility when deserializing