Improved monitoring of the obtaining of HEK event information

[wafels]

It would be good to know more about the status of the ingestion of HEK events into Helioviewer. When the process goes down it would be good to know about it.

The status page does not show the status of the ingestion of HEK event information. Perhaps the status of data injection at various frequencies should be included there so we know it's running and backfilling as expected.