Break cycles in exception stack traces

As most of the core became non-blocking, the exception stack traces became less relevant, because as the exception is re-thrown on multiple threads yet the stack trace only shows the initial thread.

ISPN-8893 improved this in some methods that are still blocking by catching an ExecutionException, adding it to the suppressed list of the cause, and rethrowing the cause. However, cycles in the exception trace is not properly supported by all loggers, e.g. logback only has a fix in the not yet released version 1.3.0.