Add Support for iiwa 7 r800

[MightyMirko]

Hola,

as wished here is some more or less running support for iiwa7 with urdf

[MightyMirko]

ros2 launch iiwa_bringup iiwa.launch.py use_fake_hardware:="false" is running properly and i can see robot moving if i move by hand

ros2 launch iiwa_bringup iiwa_test_joint_trajectory_controller.launch.py

This is not running properly. It is publishing /iiiwa_arm_controller/joint_trajectory but robot is not moving in position mode or torque mode