Publish update event, only if original source is changed.
Check changes before update event is published (~save) and processed.
E.g. when identity is saved from frontend without any change, then update and all other dependent events (e.g. provisioning) is propagated standardly. The goal of this ticket is not propagate update event at all, when nothing is changed - basic attributes and eavs have to be checked for change.
This feature will be enabled by new event property 'EntityEvent#EVENT_PROPERTY_CHECK_CHANGES=idm:check-changes' and will be disabled by default to maintain backward compatibility (current behavior is used on projects). New behavior will be used on place where is needed (e.g. in projection) from the start.