image_transport: add nodelet_lazy for image_transport

[furushchev]

In this PR, a header for NodeletLazy class is added. This is image_transport version of nodelet_topic_tools::NodeletLazy, which brings zero copy feature of nodelet into image_transport.

https://github.com/ros/nodelet_core/blob/indigo-devel/nodelet_topic_tools/include/nodelet_topic_tools/nodelet_lazy.h

related to ros/nodelet_core#75

[furushchev]

@vrabaud @jack-oquin Please could you review or merge if there is no problem?

[jack-oquin]

👍 a good idea. Thanks for doing the work!

This looks OK to me, but I don't really maintain this particular package. Vincent?

[furushchev]

@vrabaud kindly ping to maintainer

[furushchev]

@jack-oquin Maybe @vrabaud does not maintain this package anymore?
Do you have any opinion if I changed the maintainer of this package to an orphan maintainer?

[furushchev]

@jack-oquin @vrabaud Kindly ping to the maintainers.

[furushchev]

@jack-oquin @vrabaud Kindly ping to the maintainers.

[furushchev]

@jack-oquin @vrabaud @mjcarroll
Is there still any chance to make the PR be merged if I retarget it to the current active branch or is this repository read-only?
How is the situation of maintaining this repository?

[furushchev]

@jack-oquin @vrabaud @mjcarroll
kindly ping to maintainers...

[mjcarroll]

@furushchev Can you update this so that it will target noetic-devel?

[furushchev]

@mjcarroll Thank you for the response! Changed the base branch to noetic-devel branch.

[furushchev]

The test failed on debian. It seems it is not related to the change?
https://build.ros.org/job/Npr_db__image_common__debian_buster_amd64/5/console

16:18:07     from camera_calibration_parsers import readCalibration
16:18:07   File "/tmp/ws/devel_isolated/camera_calibration_parsers/lib/python3/dist-packages/camera_calibration_parsers/__init__.py", line 34, in <module>
16:18:07     exec(__fh.read())
16:18:07   File "<string>", line 1, in <module>
16:18:07 ImportError: /usr/lib/x86_64-linux-gnu/libboost_python27.so.1.67.0: undefined symbol: PyString_Type

[furushchev]

@jack-oquin @ahcorde How can we proceed with this PR?

[furushchev]

@mjcarroll @ahcorde How can we proceed with this PR?

[furushchev]

@mjcarroll @ahcorde How can we proceed with this PR?