crimson/common/errorator: construct future<> with a future_state_base

crimson/common/errorator: construct future<> with a future_state_base

this change is made to adapt
https://github.com/scylladb/seastar/commit/89e801b373423b068b3a70e50b656348f549ade0

* always use the helpers from `futurize` instead of using
  `::seastar::make_exception_future()` directly. as
  `make_exception_future(future_state_base&& state)` is located in
  `seastar::internal` namespace
* add `noexcept` specifier in both constructors. to match with the
  helpers of `make_exception_future2()` which dispatch the call to
  different constructor variants.

Signed-off-by: Kefu Chai <kchai@redhat.com>