feat!: migrate api to grpc

[matthisholleville]

Closes #380

📑 Description

This PR migrates the k8sgpt AI API from REST to gRPC, which provides a more efficient and scalable communication protocol. The protobuf files are located in the buf.build repository at https://buf.build/k8sgpt-ai/k8sgpt. The new gRPC implementation provides improved performance and reliability, while also enabling easier integration with other gRPC-based services.

✅ Checks

• My pull request adheres to the code style of this project
• My code requires changes to the documentation
• I have updated the documentation as required
• All the tests have passed

ℹ Additional Information

Log format :

(matthisholleville) ➜  k8sgpt git:(feat/grpc-api) ✗ go run main.go serve
{"level":"info","ts":1683377823.995384,"caller":"server/server.go:83","msg":"binding metrics to 8081"}
{"level":"info","ts":1683377823.9956539,"caller":"server/server.go:68","msg":"binding api to 8080"}
{"level":"info","ts":1683377830.462864,"caller":"server/log.go:48","msg":"request completed","duration_ms":289,"method":"/schema.v1.Server/Analyze","request":"backend:\"openai\"  namespace:\"k8sgpt\"  max_concurrency:10  output:\"json\"","remote_addr":"[::1]:53589"}

Query with grpcurl

(matthisholleville) ➜  k8sgpt git:(feat/grpc-api) ✗ grpcurl -plaintext -d '{"namespace": "k8sgpt"}' localhost:8080 schema.v1.Server/Analyze

{
  "errors": [
    "[CronJob] test"
  ],
  "status": "ProblemDetected",
  "problems": 1,
  "results": [
    {
      "kind": "HorizontalPodAutoscaler",
      "name": "k8sgpt/fake-hpa",
      "error": [
        {
          "text": "HorizontalPodAutoscaler uses StatefulSet/fake-deployment as ScaleTargetRef which does not exist.",
          "sensitive": [
            {
              "unmasked": "fake-deployment",
              "masked": "YnZ4TCgjMlktODs2ZyM4"
            }
          ]
        }
      ]
    }
  ]
}

[Aisuko]

Hi, thanks for your contribution. Please take a look at the suggestions.