Intraprocess prototype

ROS 2 publisher and subscriber exchange a ROS message (string
in this example) through a pointer to the data. This is useful
for intraprocess comunication where instead of transferring all
the data through the underlying dds, just a pointer (uint_64) is
transferred.

The implementation uses a struct that keeps a pointer to the data
and a count.
build publisher/subscriber for all available middleware implementations
fix the Intraprocess prototype