Previously, the DataSource initialization would back off without
spring-boot-jdbc but spring-boot-sql was a required dependency.
Without spring-boot-sql, a failure would occur due to the absence
of OnDatabaseInitializationCondition.
This commit updates the auto-configuration so that spring-boot-sql
is now an optional dependency and DataSource initialization
backs off in its absence.
Closes gh-46244
Restructure modules packages so that all auto-configuration is
organized under single top-level autoconfigure package.
See gh-46071
Co-authored-by: Andy Wilkinson <andy.wilkinson@broadcom.com>
Andy Wilkinson
Phillip Webb
Stéphane Nicoll