Generate SLA end_miss event only after confirming against persistent store

1. SLA status "MISS" which occurs on an END_MISS i.e. job overshot expected end time, is the most important sla notification for the user. We should make sure against the source of truth i.e. database, that the scenario is indeed correct for an end_miss, before setting the SLA status and sending out alerts for it

2. hanging job id getter and setter in SLASummaryBean to getId and setId to be consistent with getter in SLARegistrationBean

3. Fix bug where when Coordinator action goes from WAITING->KILLED directly, no event is received