Codify Skip-Key Definition Process

[Bckempa]

The list of rosdep skip-keys in the Dockerfiles are left without instructions for maintenance. A procedure for adding and check for removal should be developed and, if possible, automated.

Three remaining keys were still not registering correctly, this time the issue is with rosdep. All three are installed as part of the Space ROS base image, which is active as an underlay. I'm just adding them to the rosdep skip-keys list for now, which we need much better explanation of how and why these keys are chosen. I'll make a follow-up issue for that and at least break them out to a separate file like the packages.

Originally posted by @Bckempa in #228

[ivanperez-keera]

What's the success criteria here? How can we check that this is accomplished?

[Bckempa]

The long term result is we need a principled way of selecting the package and skip lists, tooling to automatically flag when they fall out of date, and potentially some feature additions to the infrastructure tooling but I tired to break all that up into some of the smallest, most actionable steps. In this case we need to investigate the warnings we are getting that skip-keys are being ignored and determine if they need to be replaced with updated packages or removed altogether. Our build process should consider these warnings as errors because it means your requested build constraints are not valid.