ignoreErrors in WC, dump shard routine, etc

[carpawell]

Is your feature request related to a problem? Please describe.

I'm always frustrated when we are not sure if it is OK to ignore every error or not: #3091 (comment).

Describe the solution you'd like

Ignore only "read" errors in processes that are about making as many saving things as possible. It makes no sense to continue flushing or dumping objects if the receiving side (disk) is not ready to take any more objects (no space left, global disk errors).

In fact, it may be already implemented but it needs to be rechecked.

Describe alternatives you've considered

The worst thing about skipping "write" errors is wasting time on useless operations. At least, it looks like. Maybe it is not that bad to really ignore every error if it was asked so.

Additional context

#3091