Add simple DB aware HealthIndicator
Adjust db type if postgres
Use additional properties instead of default args

SpringApplication (and the builder) now do not accept default
command line args because the override semantics were wrong -
you need to be able to override them with everything, including
system properties and external properties (per profile).

Also implements new semantics for profiles - you can add
additional profiles in the Java API and they will not be
squashed by command line or system properties entries for
spring.profiles.active.

[Fixes #58989906] [bs-336] DefaultArgs -> DefaultProperties