fix(engine): handle error in signal method correctly

related to #CAM-2861
chore(engine): remove spin dependency

- Spin can now optionally be added as a process engine plugin

related to CAM-2966
chore(distro): add spin process engine plugin to distro configs

related to CAM-2966
feat(FailedJobIncidentHandler): make incident available to sub-classes

related to #CAM-3005