List the runtime parameters registered on a robot, optionally filtered by a path prefix.
Returns each parameter's dotted path, current value, declared type, and the
min/max range a write has to fall inside where the robot declares one.
A parameter declared with a unit type reports its value and default as an
object carrying the magnitude and the unit name, e.g.
{"value": -12.5, "unit": "degree"}. That object is exactly what
set_parameter accepts for the same parameter.