The contact_thresh_N, contact_thresh_pos_N and contact_thresh_neg_N argument is deprecated by removing the suffix '_N' with all the move_to(),move_by(), translate_by() and rotate_by() APIs that is associated with stepper motors after the new contatc models feature introduced to the stretch_body.

This adds show_debug_images at the node level. When set to True,
debugging images are displayed via OpenCV, including RGB images
annotated with ArUco marker detections, marker masks, and depth
images used when estimating the pose of the ArUco markers.

This appears to fix an issue where the D435i's mode was
not being successfully changed on launch. The code now
sleeps for 3 seconds before trying to configure the D435i,
which appears to fix the problem for the typical launch
files in stretch_ros.

This also appears to resolve an issue that resulted in
warnings from the ArUco marker detection node and
calibration issues. Without a successful mode change,
depth images from the D435i often failed to provide
depth values for the pixels corresponding with the
ArUco markers on Stretch's body.

Addressing this issue will likely obviate the need
for Hello Robot's D435i patch that pins earlier
versions of the D435i software.

I primarily removed commented code.

Node that outputs d435i frustums now works with ROS Noetic, etc.
I've also added a new launch file to more easily test and
visualize the frustums. It has an associated rviz configuration
file.