Summary:
Moved the ysql catalog config to `YsqlCatalogConfig` in `ysql_catalog_config.cc`.
Refactoring changes only. No functional changes made.
Jira: DB-13837

Test Plan: Jenkins

Reviewers: fizaa

Reviewed By: fizaa

Subscribers: svc_phabricator, ybase

Differential Revision: https://phorge.dev.yugabyte.com/D39659