Support zilla start ... --diagnostics-directory to capture engine state #1663
Description
This is useful to capture diagnostics about internal state of the engine.
We should be able to trigger this in the following cases:
- on exit with non-zero status, perhaps due to an exception
- on receiving a signal such as SIGUSR1 to get a snapshot of the engine state at a point in time
The name of the generate archive should include a date time stamp so that multiple archives do not overwrite each other.