[Feature request] Dump all threads stacktraces in case of watchdog timeout

[tosiara]

I don't know if that is possible at all or how hard is it to implement, but maybe we could dump stacktrace of all threads into the debug logging (-d 9) in case we hit a watchdog timeout? This would allow us to see which function is blocking the thread and that would help to troubleshot issue faster, like this: #1541