Switched build tool from catkin to colcon

[pascalau]

This PR allows to build VRPN in the new ROS2 build system Colcon. This PR has been tested on my side against rolling but it should build against all recent ROS2 releases.

Requirements

• A ROS2 base install
• Colcon

$ mkdir -p ros2_ws/src && cd ros2_ws
# apt install ros-rolling-ros-base ros-dev-tools # ROS repository has to be added beforehand
$ source source /opt/ros/rolling/setup.bash
$ cd src && git clone https://github.com/pascalau/vrpn_catkin.git -b ros2 && cd ..
$ colcon build --symlink-install

Notable changes:

• Switched from URL based fetching of code to Git to allow easier updating of Versions.
• Renamed package to make naming agnostic of build system
• Added Linting tests (not currently tested if they pass)

[TannerGilbert]

@michaelpantic thanks for merging this. For ROS 2 Humble and a few other versions a further change is needed to get this working #10