[Feat] migrate code from ros1 to ros2

[sujit-168]

The key migration part occurs in the following commits, other commits are about minor changes.

1. migration *.cpp and *.h files
2. migration CMakeLists.txt and package.xml files
3. migrating launch .xml to launch.py
4. migrate param loading from *.yaml
5. migrate rviz to rviz2

[james-ward]

@sujit-168 I have added a couple of new commits to your work, so that the parameters are set on the main node properly:
https://github.com/integralrobotics/FAST-LIVO2

Also, your version of Vikit isn't public, so the version I have compiled against is here: https://github.com/integralrobotics/rpg_vikit.git

I was thinking about modernising the CMakeLists.txt file to use a cleaner approach, if you are interested in that as well.

[sujit-168]

@james-ward Thank you for contributing to this pull request, especially for open-sourcing your completely modified solution. Your modifications to Vikit are another interesting approach.

[james-ward]

I have put in a PR to your original branch: Robotic-Developer-Road#1

[sujit-168]

@james-ward Regarding the way to read camera parameters, my suggestion is to keep two solutions so that the community can refer to them. This issue can have more discussions.

[james-ward]

@james-ward Regarding the way to read camera parameters, my suggestion is to keep two solutions so that the community can refer to them. This issue can have more discussions.

Sure. But until you release the version of Vikit you are using I couldn't get your method to work.