In our Netty layer we have had to take extra precautions against Netty
catching throwables which prevents them from reaching the uncaught
exception handler. This code has taken on additional uses in NIO layer
and now in the scheduler engine because there are other components in
stack traces that could catch throwables and suppress them from reaching
the uncaught exception handler. This commit is a simple cleanup of the
iterative evolution of this code to refactor all uses into a single
method in ExceptionsHelper.