Remove intersitial task events - implement Upsert

[rosibaj]

Different task status are captured as events.

• the completed event should replace the interstitial events so that the only remaining status is the correct end-state for the tasks of (completed vs executor error)
• final task event contains - how long it was queued/running

[rosibaj]

@andricDu Are there any deploy events left here?

[andricDu]

@rosibaj I was waiting for the elasticsearch sharding changes to be done by @lepsalex so it can all be done at once at reindex.