Interesting point about adding more user-error checking to IK solvers. We could take inspiration from the constraint_sampler_allocator plugin and call the function ``canService`` as seen [here](https://github.com/ros-planning/moveit_core/blob/hydro-devel/constraint_samplers/include/moveit/constraint_samplers/constraint_sampler_allocator.h#L58). 

@isucan implied in our discussions I should take out these safety checks for kinematic chains, they just enforced assumptions at the time

+1 to descriptive texts