Add test_controller ros2 package

[martinaxgloria]

As per the title, this PR adds a ros2 package called test_controller. It contains:

• A simple C++ code that creates a node that uses MoveIt2 tools to sample the workspace and compute a set of trajectories in the Cartesian space;
• A launch file that is used to launch the node previously discussed;
• A report in which the design of the tests and how they were carried out are described, with the related plots generated in Matlab;
• A folder called utils with the 2 Matlab scripts I used to obtain the plots.
• Some other little fixes

I open this PR mostly for the report part, in order to be sure to have not missed anything important and/or to understand it is all clear to someone who is not me.

[Nicogene]

Great work! 🎖️