Explore patterns to load different skill sets when launching in ROS 2

[matthias-mayr]

In ROS 1 we had patterns to load different sets of skills depending on arguments in the launch files. For example:

  <arg name="fake_vision" default="true"/>

  <arg if="$(arg fake_vision)" name="fake_vision_suffix" default="_fake"/>
  <arg unless="$(arg fake_vision)" name="fake_vision_suffix" default=""/>

  <arg name="skill_list" default="[object_localization$(arg fake_plugging_suffix),

This would load object_localization_fake if fake_vision is set.

It would be great to explore some patterns for ROS 2.