Network: add debug support to catch exception generated by processes

Lots of application can misbehave because there is an exception happening inside one of the process.
This usually cancel an entire branch of data exchange within the graph of the application, because there is nothing to actually catch the exception.

This patch is a first iteration of a exception/error detection within processes. This could probably improved with collection of errors happening on unattached error ports and also deal with async components probably mostly inside WirePattern.