Borrow ids from a next millisecond

[azzz]

At the current moment, the service responds with StatusServiceUnavailable when the incremental number gets overflown.
It works well in general, but becomes too noisy when the service experiences a burst growth of requests.
In such cases, the service should borrow ids from a next millisecond and handle it carefully, it must not generate another ID from an already borrowed timestamp when the burst stops.