refactor IndexEventLog a bit to simplify type/action information. prep for serializing IndexEvent objects to Metacat. https://projects.ecoinformatics.org/ecoinfo/issues/5944
remove serial number from indexeventlog - it is not used elsewhere in the api. https://projects.ecoinformatics.org/ecoinfo/issues/5944
adding ability to remove event from the [error] queue.
It will make the index only for those objects which were modified after the marked time.
Add set and get the lastprocessedDate in the IndexEventLog.Remove the code to write the successful event.
Add a serial number for the event.Add method to set events to be archived.
Add a new class variable - isArchived for class IndexEvent.
Update the documentation about those classes.
Add a event and eventlog for the index.