Add ability to use capability-provided integrations from services and DUPs

The service name discovery and custom runtime integration API features of WildFly Core managed capabilities are currently only accessible directly from the OperationContext. Add a mechanism for services to look up capability-based service names and runtime APIs.

The OperationContext will make this facility available. OSHs can then provide it to services they create.

The immediate use case for this is the deployment related OSHs can provide this to RootDeploymentUnitService. From there it can be exposed to DeploymentUnitProcessors via the DeploymentPhaseContext.