Add a tool for calibrating the nav camera

[hello-amal]

In the web teleop interface, multiple people have pointed out how it would be easier to access the depth-related features (depth sensing overlay, click-to-pregrasp) on the nav camera instead of the realsense. The key blocker for this is having access to the nav camera's intrinsics matrix, which is required to convert the depth data from the D435's frame to the nav cam's frame.

Thus, this issue is about creating a stretch_body tool to get the intrinsics matrix of the nav camera. This can then be added to the bringup calibration process, and then stretch_ros2's usb_cam can read it in as a parameter and publish it on a CameraInfo topic.