Handle commit rollback programatically instead of throwing exceptions

[ppazos]

Here explains how to do it, this is clearer and more controlled, but needs some refactoring.

https://stackoverflow.com/questions/21138173/grails-saving-multiple-object-rollback-all-object-if-one-fails-to-save

[ppazos]

Check

https://stackoverflow.com/questions/27016302/grails-rollback-withtransaction-on-save
https://stackoverflow.com/questions/28242153/grails-2-4-4-how-to-reliably-rollback-in-a-complex-service-method