[TEST] Change es.node.mode default for tests to `local`

In order to speed up test execution we should run in local mode by
default. CI builds will still use network builds all the time.

Closes #6624
Add RedistributingCircuitBreakerService

Also adds a breaker for request BigArrays
Add unit tests for setting validation
Remove test that became a unit test
Flush every 5mb, document why a flush is needed before decrementing
.toString() implementation for BreakerStats
Adjust breaker back down after closing AbstractArray
Max flush() private
Change some of the default sizes for the breaker service
BigArrays buffer flushing, without locks! Magic!
Add `testBreakerRedistribution()` test