Add Multicamera support

[AADad578]

Use up to 4 realsenses and a lidar. Can disable some cameras with arguments on launch.

Valid Configs:
4 cameras + lidar -> back = true, front = true, extras = true, lidar = true

• Will create and combine pointclouds for cameras, assemble lidar pointclouds over time, and combine both to give to rtabmap
  4 cameras -> back = true, front = true, extras = true, lidar = false
• Will create and combine pointclouds for cameras, and send that to rtabmap
  2 cameras + lidar -> back = true, front = true, extras = false, lidar = true
• Will create and combine pointclouds for just 2 cameras, assemble lidar pointclouds over time, and combine both to give to rtabmap
  2 cameras -> back = true, front = true, extras = false, lidar = false
• Will create and combine pointclouds for just 2 cameras, and send that to rtabmap
  1 camera -> back = true, front = false, extras = false, lidar = false
• Will send just rgb and depth images to rtabmap

Will always send rgb and depth of back cam to rtabmap for odometry.
Runs all cameras at 424x240x30fps, any more quality reduces refresh rate too much.
Currently runs all cameras at around 15 hz pointcloud generation.