[image_geometry] Migrated to ROS2

[akhileshmoghe]

Changes include:

1. Enabled pytests in image_geometry package.
2. Code modified for ROS2 colcon build & test errors, all tests passed.
3. Cosmetic tests - test_copyright, test_pep257, test_flake8 passed.
4. Merged Approved changes from PR [image_geometry] Enable python package installation #257.

@mjcarroll
Please review this PR, Thanks.

[akhileshmoghe]

@gaoethan Will you please review this PR?
I have tested these changes on Crystal release also, all above mentioned tests have passed.

[mjcarroll]

@akhileshmoghe Can you go ahead and rebase this on current ros2 branch and I'll kick off CI, thanks.

[akhileshmoghe]

Hi @mjcarroll
I have resolved the conflicts and the build error introduced after accepting PR #257 changes.
Kindly review changes.

[klintan]

Looks good to me, we have some duplicated effort and concerns/thoughts here:

#295

[mikaelarguedas]

Sorry @akhileshmoghe I have not been the maintainer of this package for a long time and don't have authority here.
I believe @mjcarroll can review or point to the current maintainer of this.

---

It seems that a much younger PR with essentially the same source changes got merged as pointed out by @klintan

Here's a review based on what I remember from the time of the original ROS 2 port:
In the end I think only the necessary code changes in directed.py should be kept and rebased on top of the latest state, the rest of the changes seem IMHO unnecessary or unwanted

• style was not updated when porting from ROS 1 to keep the diff with the ROS 1 branch minimal. Following that logic, the linter tests and style changes should be removed from this PR
• The copyright notice and license changes to the existing files seems wrong. These files were written before 2018, also before OSRF existed and under a different license (most likely BSD).
• The content of the migration readme and PR title is misleading, as this package's C++, package.xml, CMake etc was already ported to ROS 2. At the end of the day, this PR is only updating message field names which I believe doesn't need a dedicated README