Test and use rclpy events executor

[texhnolyze]

Summary

Corresponding to the C++ events executor, there was just recently implemented a corresponding rclpy events executor.

We want to test this and compare performance of the implementation with our current ROS software stack compared with the classic executors.

Describe the solution you'd like

• backport events executor from rolling to jazzy if necessary
• test python events executor with our software
• test for problems with deadlocks etc.
• run some performance benchmarks to get some qualitative comparable results