Mechanism for inspecting the status of the kernel.
In particular this provides functions for getting the status of processes on the board. It potentially could be expanded to other kernel state.
To restrict access on what can use this module, even though it is public (in a Rust sense) so it is visible outside of this crate, the introspection functions require the caller have the correct capability to call the functions. This prevents arbitrary capsules from being able to use this module, and only capsules that the board author has explicitly passed the correct capabilities to can use it.