Make real-time options configurable

[carlossvg]

Is your feature request related to a problem? Please describe.

The autoware_default_prioritized uses hardcoded priorities and affinities. It would be interesting to make this more flexible so different configuration can be used.

Describe the solution you'd like
I wonder if it makes sense to make these priorities and affinities configurable. For example, using command-line options or a YAML file.

Describe alternatives you've considered
Another option would be to reconsider the hardcoded values and at least raise the priorities above 50, above interrupt threads priorities.

Additional context

This request is part of the work we are doing for https://github.com/ros-realtime/ros2_realtime_benchmarks. I would like the priorities and affinities to be consistent with other benchmark tools we are using.

[carlossvg]

FYI @flynneva @ralph-lange