Further work on the Provider resources.

[darranl]

Where the service returns a list of providers we should also be able to include the globally registered providers.

Also one list could possibly reference another list, this way small definitions can be created followed by an aggregation.

[darranl]

Also consider if it makes sense for it to be wrapped using a Supplier<Provider[]> - this could make more sense once the globally registered providers are also returned as these may be subject to change.