Better view of execs/forks

[lacraig2]

Our view of processes in execs.py exclusively works from various syscalls like execve, execveat, etc.

This is a limited view of executions in the system because the kernel can execute processes on its own.

I'm considering using kernel tracepoints for this sort of thing:

https://docs.kernel.org/core-api/tracepoint.html

using trace_sched_process_fork, sched_process_exec, and trace_sched_process_exit would help with this sort of thing.

Could also be helpful to detect hung tasks using sched_process_hang.