HumidityControlSetpoint Command Class
@type scale() :: :percentage | :absolute
@type type() :: :humidify | :dehumidify | :auto
@spec decode_scale(byte()) :: scale() | :unknown
@spec decode_type(byte()) :: type() | :unknown
@spec encode_scale(scale()) :: 0 | 1
@spec encode_type(type()) :: 1 | 2 | 3