An abstraction to implement blocking Raft ops. A blocking Raft op requires
caller information to be provided before the Raft op is being replicated
and committed by the Raft consensus algorithm. The Raft invocation mechanism
provides this functionality. Once the Raft op is committed, it is reported
as a live operation to the Hazelcast's invocation system, even if the total
wait duration is longer then the configured operation timeout duration.
A blocking Raft op can fail with operation timeout if it is not committed
before the configured operation timeout duration passes.