Added ros2 support

• Tested on ubuntu 20.04, foxy
• Added interprocess communication capabilities
• Added more logging (buffer empty / no image in buffer)
• Added install instructions in readme.
• Added config files for testing
• Separated interfaces (msg/srvs), I think there is an issue or its intended to keep interfaces separate in ros2. Currently they are here.
• Once we confirm this is working, I'll add them here like the following structure. Didn't add directly as this would make this PR difficult to review.

rc_genicam_camera/
├── rc_genicam_camera
│   ├── CHANGELOG.rst
│   ├── CMakeLists.txt
│   ├── LICENSE
│   ├── README.md
│   ├── cmake
│   ├── config
│   ├── include
│   ├── launch
│   ├── package.xml
│   ├── rc_genicam_camera_nodelet.xml
│   ├── rosdoc.yaml
│   ├── run_clang_format.sh
│   └── src
└── rc_genicam_camera_interfaces
    ├── CMakeLists.txt
    ├── msg
    ├── package.xml
    └── srv

Hardware used for tests

• Genicam compliant Flir and Basler GiGE cameras

Build and Install

cd ros_ws/src/
git clone <this repo>
cd rc_genicam_camera
git checkout <ros2 branch>
cd ..
git clone https://github.com/MRo47/rc_genicam_camera_interfaces
cd ..
rosdep update
rosdep install --from-paths src -y --ignore-src
colcon build

Run and check camera node

# from ros2_ws
# modify camera config files in `config`, run colcon build again after any mod as they need to be installed
source install/setup.bash
ros2 launch rc_genicam_camera rc_genicam_camera_launch.py

# in another terminal from ros2_ws
source install/setup.bash
ros2 run rqt_image_view rqt_image_view
# select relevant topic /image_raw

Required input

• Might have to keep this in separate ros2 branch? or I'm happy to keep in my github
• Remove nodelet xml? as there are no nodelets in ros2
• Cleanup package xml (dynamic reconfigure not sure what it does and if required, maybe lifecycle node does the same)
• Cleanup cmakelists (the commented out install part, dont think its required anymore?)

TODO / Might cover in future PR

• Lifecycle nodes

Closes #3