Add workload services

[AmartC]

This PR adds the specs for the workload and pretrained DRAIN services as well as the specs for the CPU and GPU inferencing services and the training controller.

[dbason]

In general this looks fine.

To fix the compilation errors you will need to update the ConvertSpec function in /pkg/resources/opnicluster/util.go and replace

services.Drain = v1beta2.DrainServiceSpec(input.Services.Drain)

with

services.Drain = v1beta2.DrainServiceSpec{
    ImageSpec: input.Services.Drain.ImageSpec,
    Enabled: input.Services.Drain.Enabled,
    NodeSelector: input.Services.Drain.NodeSelector,
    Tolerations: input.Services.Drain.Tolerations,
    Replicas: input.Services.Drain.Replicas,
}

You will also need to remove the commented lines from /controllers/ai_opnicluster_controller_test.go. Also please look into adding tests for the new services you have added.

[dbason]

You also need to remove the section in /pkg/resourcees/opnicluster/opnicluster.go that logs about GPU learning not being supported. It starts on line 166

[kralicky]

LGTM