Zultron/2022 09 19 rebase for PRs: 2 minor ros

[zultron]

This is 2 of 9 in a series of PRs refactoring the hw_device_mgr to run outside ROS, handle file resources more intelligently, manage PDO configurations, improve abstraction, improve CiA402 homing, simplify initialization, fix a state_cmd race condition, and other fixes and improvements.

This PR is based on & should be merged after #14 .

This second PR makes changes related to ROS:

• Add plain Python logging class for use outside of ROS
• When a test can't import rclpy, skip those tests for use outside of ROS
• Convert to ament_python ROS package; reduces LOC; packaging shared with non-ROS use cases
• Fix forgotten ROS1 code left in non-ROS manager update loop

[kylc]

I'm getting this error when building. Maybe something just got out of order in the PRs?

--- stderr: hw_device_mgr                                                                                                                        
package init file 'hw_device_mgr/devices/device_xml/__init__.py' not found (or not a regular file)
---

Otherwise looks good!

[zultron]

Thanks, @kylc , you got it, devices/device_xml/__init__.py should have made it into PR #14, but was added in PR #16 instead. I re-added it here. Merging....