Full Gazebo simulation support

[quantum9Innovation]

One of the most requested features after the informal proposal of the Nix build system to the Arcturus Autonomy subteam has been the addition of support for Gazebo simulation, as–for better of for worse–it remains a critical part of how code is tested before being deployed. There does not exist any pre-existing Nix package for Gazebo due to the Ubuntu lobby, so this will likely need to be worked on before checking that the Gazebo package can interface with ROS nodes in the Nix environment.