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
chore(db-upgrade): remove unused dependency

related to CAM-2966
chore(engine): remove connect from engine

related to #CAM-2706
chore(pom): use connect SNAPSHOT until next release also use BOM

related to #CAM-2741
chore(engine): add scope key to variable scope

related to #CAM-2706
chore(engine): allow service task parse listener to add behavior

related to #CAM-2706
chore(pom): add connect dependency to distro and standalone webapps

- also add connect plugin to process engine configuration of distro
  and standalone webapps

related to #CAM-2706