Add NoopCircuitBreaker used in NoneCircuitBreakerService

This adds the NoopCircuitBreaker, which is used in the
NoneCircuitBreakerService when the overhead of a circuit breaker is
undesired.

In order to use it, the setting `indices.breaker.breaker_impl` can be
set to `org.elasticsearch.indices.breaker.NoneCircuitBreakerService`.

This also adds a benchmark for CircuitBreakerService implementations, so
that the overhead of the circuit breaker can be measured.