A struct to represent the MessagePack Binary type.

Elixir binaries are serialized and de-serialized as MessagePack strings: Msgpax.Bin is used when you want to enforce the serialization of a binary into the Binary MessagePack type. De-serialization functions (such as Msgpax.unpack/2) provide an option to deserialize Binary terms (which are de-serialized to Elixir binaries by default) to Msgpax.Bin structs.