v.23.4Experimental Feature

Some fixes for parallel replicas #48433 by Nikita Mikhaylov

Some fixes for parallel replicas #48433 (Nikita Mikhaylov).
Fixes for parallel replicas synchronization in ClickHouse.

Why it matters

Improve the stability and correctness of the parallel replicas feature by addressing known issues in replica synchronization and data consistency.

How to use it

The fixes are applied automatically with the update to the new ClickHouse version containing this patch; no additional user configuration is required. Users benefit from improved replica synchronization out-of-the-box.