Summary:
Original commit: baf60e28e6aeeeecb9370567a67b5c8730ade30a / D43625
This change prevents the creation of nonconcurrent indexes on tables that are part of a non-automatic xCluster replication group.
Nonconcurrent indexes if created on the target cluster would result in duplicate records, causing data inconsistency between the source and target clusters.

Fixes #27006
Jira: DB-16482

Test Plan: XClusterYsqlTest, NonconcurrentBackfills

Reviewers: jhe, fizaa

Reviewed By: jhe

Subscribers: yql, ybase

Differential Revision: https://phorge.dev.yugabyte.com/D43652