!con #16123 Expand cluster roles support in ClusterSharding

Allow a roleOverride: Option[String] to be used when starting ClusterSharding for a given entry type. This will allow role defined clusters of ClusterSharding for entry types instead of requiring the role configuration to be all or nothing across all entry types.
Merge pull request #16136 from rmarsch/entryRoleOverride-#16123

ClusterSharding: Expanded cluster roles support