Bulk API: Fix return of wrong request type on failed updates

In case an update request failed (for example when updating with a
wrongly formatted date), the returned index operation type was index
instead of update.

Closes #6630
Refactoring: Replaced string values with static constants

in TransportShardBulkAction after fixing an issue.
Add RedistributingCircuitBreakerService

Also adds a breaker for request BigArrays