Replicate objects only if `HEAD` response means object missing

[carpawell]

Revise replication logic. Currently, any error that is not NotFound leads to replication, even if the HEAD response:

1. says AccessDenied;
2. could not answer at all until timeout expiration;
3. *any other reason that says nothing about object presence*.

That leads to network operations that could be useless. Also if a cluster is under critical load, continuous replication made that even worse.

Maybe that is an arch issue and we should allow SN's HEADs always.

[alexvanin]

Related to TrueCloudLab/frostfs-api#5