v.20.5Bug Fix

Fix Optimization of Predicates in Distributed Queries with HAVING Clause

Fix predicates optimization for distributed queries (enable_optimize_predicate_expression=1) for queries with HAVING section (i.e. when filtering on the server initiator is required), by preserving the order of expressions (and this is enough to fix), and also force aggregator use column names over indexes. Fixes: #10613, #11413. #10621 (Azat Khuzhin).