What this PR does / why we need it:

This PR adds capability in feast-operator to allow user to deploy registry serving in REST or gRPC or both mode.

New configuration fields:

• GRPC: Toggle gRPC server (--grpc/--no-grpc)

• RestAPI: Toggle REST API server (--rest-api)

• When REST API is enabled:

  • Creates separate service with -rest suffix
  • Configures dedicated REST API port
  • Supports both HTTP/HTTPS

• Service hostnames:

  • Separate hostname for REST API endpoints
  • Format: {service-name}-rest.{namespace}.svc.cluster.local:{port}

• Maintains backward compatibility with existing gRPC deployments.

Setting restAPI: true will deploy registry with :
feast serve_registry --rest-api

spec:
  feastProject: example
  services:
    registry:
      local:
        server:
          restAPI: true
          grpc: true

Additionally, also fixed the issue in f231f0d with rest port not used when grpc is disabled and only rest-api is enabled. Earlier it was using default grpc port instead of default rest port.