Decoupled the additional feature from rclcpp to rcpputils, reflecting…

[smorita-esol]

feat: Thread configuration prototype

This PR is to decouple the new feature included in the PR of rclcpp below into rcpputils. https://github.com/ros2/rclcpp/pull/2205

REFS: https://github.com/ros2/rclcpp/pull/2205#issuecomment-1593832758

[smorita-esol]

@carlosssv Reflecting the point raised by you, I've added an interface to make each thread be able to configure the attributes by itself.

https://github.com/ros2/rcpputils/pull/179/commits/7d35f5fdabff4400ba6787bf5f6455b0aa7f0ba1