Update the subsystem to be exposing CDI beans using gRPC

[darranl]

In theory it should be possible to register a CDI Extension to process CDI beans as they are defined, with this we can check for annotations / interfaces implemented etc.. and handle the gRPC registration.

This issue is to cover the current deployment type, follow up issues may be created for:

• Injection of gRPC resources if any are useful.
• Alternate deployment approaches / annotations.

[jamezp]

We probably want to handle the gRPC registration via a DUP and Jandex. While I still think a CDI Extension could be useful, I'm not sure we want to determine registration based on that.

[darranl]

+1 the decision to activate gRPC for the deployment will need to be a traditional DUP / Jandex scan - we only want to activate the CDI extension after we have confirmed the deployment needs gRPC.