Add support for No-Op Value

[tnovotny]

If I read the source code correctly then the No-Op value is not considered. This is especially important for the streams.

[tnovotny]

just saw the
enum class Marker : byte { ... No_Op = 'N',
so I think this can just be closed

[WhiZTiM]

You are right, while we do have the Marker::No_Op marker, I didn't consider it in the StreamReader. StreamWriter not having it can be an acceptable temporary limitation. However, it is definitely a bug that StreamReader doesn't have it. (What if we are reading UBJSON binary stream written by another client?).

Thanks! Added to my TODO list this weekend.