Introduce a base "health" subsystem and move microprofile-health to the microprofile feature-pack

The microprofile-health-smallrye subsystem is provided by the wilfdfly galleon-pack.
However its logical inclusion is in the microprofile feature pack (org.wildfly:wildfly-mp-feature-pack-galleon-common) which provides features for MicroProfile.

We should move the subsystem (and extension) to this feature pack.

However, the base WildFly server is still expected to provide "base" healthiness information (to determine when the application server is ready to serve requests) that can be consumed out of the box by a container platform such as Kubernetes.
I propose to introduce a simple "health" subsystem (without any external dependencies) that provides a HTTP endpoints to probe the server healthiness.

The microprofile-health-smallrye subsystem will be refactored to "plug" in the same HTTP endpoint and overrides the base health endpoint and provide the full features of MicroProfile health