cloe-osi contains strange implementation for has_sensor_view()

[cassava]

          Isnt sizeof(osi3::SensorView) the size of the deserialized protobuf message whereas the size of the message in the tcp buffer is serialized?

In my point of view the amount of data in the buffer does not give any information on which osi message is in the buffer

Originally posted by @hvolx in #223 (comment)