Specific Types for functional interfaces with generic types

Using MSC and WildFly Core's Capabilities and Requirements support there is a limit as to how far we can go with generic and maintain type safety.

For any type returned by a factory method we should have a type that extends from the functional interface with the geeneric types specified e.g.

  ProvidersSupplier extends Supplier<Provider[]>

Code that depends on this can still depend on Supplier<Provider[]>