[kinova_description] Make limits optional and add input validation
[kinova_description] Make limits optional and add input validation

Kinovarobotics/kinova-ros,Kinovarobotics/kinova-ros,Kinovarobotics/kinova-ros,Kinovarobotics/kinova-ros,Kinovarobotics/kinova-ros,Kinovarobotics/kinova-ros