This fixes many issues with the current archive cli which prevented it from
working:
- cli.task: Use the configuration provided by the cli
-> it was no longer using the config provided, so failing to initialize the
elasticsearch client.
- cli.task: Tasks needs to be sorted prior to group by call
-> otherwise the initial group by's point is moot
- backend_es: Open indices prior to indexing method calls (and close it back
when done)
-> in production, most old indices are closed. So we need to open them, do
our bidding, then close.
- backend_es: Create index when it does not exist
-> new indices need to be created since the last time the cli ran...
Depends on D2457