Ensure correct treatment of damage to spare ranks

[rfvander]

Right now in the test programs we have, including the Fenix-fortified PRK, we observe what happens when an active rank kills itself. We don’t have a structured mechanism to introduce errors in spare ranks, and I am pretty sure we don’t fully cover that case now. I can show you with the PRKs as an example. Instead of issuing a sigkill from inside the code, I can start a long-running case in the background, fetch rank PIDs, and issue “kill -9 PID” from the console, shooting down active OR spare ranks. Results are not very consistent, although the code always finishes and passes the verification test