Use ROS parameters instead of services for ROSflight params

[bsutherland333]

Something that would be a useful improvement to rosflight_io is to switch the method of interacting with ROSflight params over the ROS network. Currently, to change or view a parameter, a ROS service call is used. Unfortunately the syntax for a command line ROS 2 service call has gotten messier and less convenient since ROS 1. However, ROS has a built in parameter system that is much easier to interact with and is integrated with tools like rqt_reconfigure and core ROS CLI tools.

Switching rosflight_io parameters to use the ROS parameter system should be a relatively easy change that would improve the usability of rosflight significantly.

Implementing this should only require changes to rosflight_io.hpp and rosflight_io.cpp.