Fixes for problem_generator.py

[trey0]

This is a pretty big code change that amounts to a pretty minor tweak to the planning model semantics but with some nice side benefits.

Main changes:

• Previously, problem_generator.py output a PDDL problem instance in the format accepted by PDDL planners. However, when using PlanSys2, the PlanSys2 problem expert is in charge of generating the problem instance based on the knowledge incrementally built up by a sequence of PlanSys2 API calls. With this update, problem_generator.py is now compatible with PlanSys2. When run with --terminal, it generates a sequence of commands for the PlanSys2 terminal that will trigger the right API calls to the domain expert that should cause it to output an equivalent PDDL problem instance.
• In the planner model and supporting scripts, we removed the run-number argument from stereo and panorama actions. We now think it's better to track run number using a counter outside of PlanSys2 so that the numbering state can persist across a PlanSys2 restart. A side benefit is a surprise ~60% reduction in planner run-time.
• Another minor tweak is that we no longer specify num_orders in the config file, but rather we calculate it automatically based on the maximum order number used in the goals. This shrunk num_orders from 10 to 5 and further reduced planner run-time ~50%. (We might end up padding num_orders a bit again if we decide we need more flexibility to add new goals on the fly.)
• Previously, problem_generator.py hard-coded the config file split between the "static" and "dynamic" configs. We've retained that split in the example inputs, but the script can now accept an arbitrary list of config files as long as they together contain all the necessary fields.
• The scripts previously could be run for testing with their default arguments (which pointed to valid example files), but that got broken by a previous PR when everything was sorted into subfolders. Restored now.

[Bckempa]

Plansys2 (specifically DomainReader) does not handle multi-line predicates as you'd expect. This has been reported upstream (PlanSys2/ros2_planning_system#286) but for now we need to axe the new-lines.

[Bckempa]

Plansys2 (specifically DomainReader) does not handle multi-line predicates as you'd expect. This has been reported upstream (PlanSys2/ros2_planning_system#286) but for now we need to axe the new-lines. (Github won't let me create a suggested change because the range encompasses a deleted line? That seems like a major limitation)

[Bckempa]

Same issue as the other comments, but this time it lets me use the suggestion feature. Just make sure to apply to all three multi-line predicates:

Suggested change

	(completed-let-other-robot-reach
	?robot - robot
	?order - order
	?loc - location
	)
	(completed-let-other-robot-reach ?robot - robot ?order - order ?loc - location )

[Bckempa]

Discussed this with @bcoltin and we're going to merge this to keep testing unblocked