Obelisk C++ library

[Zolkin1]

Implementing the C++ side of the Obelisk generic ROS2 interfaces.

• [x] ObeliskNode
• [x] ObeliskController
• [x] ObeliskEstimator
• [x] ObeliskSensor
• [x] ObeliskRobot
• [x] ObeliskSimRobot
• [x] MujocoInterface
• [x] Shielding

TODOs:

• [x] Update all "settings" to be "setting" when referring to a single array
• [x] Add logging for each node state change (include node's name)
• [x] Make all the on_* functions virtual so they can be overriden
• [x] Fix timing conversion issues
• [x] Deal with publisher activation warnings (there might be a better way to do this...)
• [x] Deal with graceful exit on the mujoco sim
• [x] xhat not being populated
• [x] Change all REQUIRE in Catch tests to CHECK so that we don't get cascading issues.
• [x] Clear up warning from the GLFW callbacks when using ros-build

[Zolkin1]

Change the names for the Obelisk Publishers and Subscribers to be more clear.