KUBE-503: adjust Github workflows, adjust for latest Proto definitions and add e2e test

[Trojan295]

I used the following resources on Tilt cluster to expose a gRPC server for testing:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/backend-protocol: GRPC
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
    nginx.ingress.kubernetes.io/auth-response-headers: Grpc-Metadata-user-token, user-token
    nginx.ingress.kubernetes.io/auth-url: http://gatekeeper.console.svc.cluster.local:8080/v1/strict
  generation: 1
  name: public-cloud-proxy-grpc
  namespace: default
spec:
  ingressClassName: internal
  rules:
  - host: grpc-damianc.localenv.cast.ai
    http:
      paths:
      - backend:
          service:
            name: cloud-proxy
            port:
              name: grpc
        path: /gcpproxy.CloudProxyAPI/StreamCloudProxy
        pathType: ImplementationSpecific
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: cloud-proxy
  name: cloud-proxy
  namespace: default
spec:
  ports:
  - name: "grpc"
    port: 50051
    protocol: TCP
    targetPort: 50051
  selector:
    app: cloud-proxy
  type: ClusterIP

Then created a deployment cloud-proxy and used Telepresence to intercept it and run the gRPC server locally.
https://www.getambassador.io/docs/telepresence-oss/latest/howtos/intercepts

telepresence intercept cloud-proxy -p 50051

❯ go run ./e2e
[CLOUD-PROXY-E2E] 2024/09/03 15:12:00 starting response returning loop
[CLOUD-PROXY-E2E] 2024/09/03 15:12:09 Received a proxy connection from client
[CLOUD-PROXY-E2E] 2024/09/03 15:12:09 Starting response receiver
[CLOUD-PROXY-E2E] 2024/09/03 15:12:09 Starting request sender
[CLOUD-PROXY-E2E] 2024/09/03 15:12:09 Sending request to cluster proxy client
[CLOUD-PROXY-E2E] 2024/09/03 15:12:09 Sending request to cluster proxy client
[CLOUD-PROXY-E2E] 2024/09/03 15:12:09 Sending request to cluster proxy client
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Got a response from client: d50a51d5-0e57-47dc-b2d7-eeb297e36a88, 200
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Sent a response back to caller
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Received a response back from dispatcher d50a51d5-0e57-47dc-b2d7-eeb297e36a88
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Got a response from client: 1ff9f13a-b48c-47ac-9ffe-1193378175a3, 200
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Sent a response back to caller
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Received a response back from dispatcher 1ff9f13a-b48c-47ac-9ffe-1193378175a3
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Got a response from client: b21666ee-9771-41f1-a7d1-82c6a8dc2eed, 200
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Sent a response back to caller
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 Received a response back from dispatcher b21666ee-9771-41f1-a7d1-82c6a8dc2eed
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 stream closed, stopping sending responses
[CLOUD-PROXY-E2E] 2024/09/03 15:12:10 TEST PASSED: basic test