Add BreakException class to ThrowException action, indicates break in flow without error

This change alters the ThrowException action to use by default a specific BreakException for leaving the form processor without replacing the output handler with error data. Allows you to indicate that breaking execution at that point is expected, which was the original point of the ThrowException action. Added a configuration option to indicate an error as before.

Without companion MR form-processor!102 (merged) this will continue the existing behaviour where the BreakException is caught as a Throwable with rollback avoided, but replaces the output handler with error data.

Agileware ref CVAP-75