Write more `hw_interface` tests

Using the [provided example](https://github.com/ros-controls/ros2_control/blob/humble/hardware_interface/test/mock_components/test_generic_system.cpp) from the official [ros2_control docs](https://control.ros.org/rolling/doc/ros2_controllers/doc/writing_new_controller.html) it is possible to write more automatic tests for the HW Interface.

Right now we have only one tests for loading the URDF in the `robotiq_hande_driver/test/test_load_hw_interface.cpp` file.