Add TCPROS layer to contrib (#3462)

* Add TCPROS layer to contrib

The Robot Operating System (ROS) is a framework for robot
application development which provides modular distributed
software for building a variety of robot applications.

This layer allows to dissect ROS's (ROS 1) TCP-based communication
middleware.

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Flake8 adjustments

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Fix spell checking

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Remove debug leftovers, group them under conf.debug_dissector

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Remove global nfields, use __slots__

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Remove globals also from TCPROSBody

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Fix global var. leftovers, transform to __slots__

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Simplify license

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Bind TCPROS tests to 11311

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Deal with flake8 issues

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

* Address codacy issues

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>

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Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>