Make query kind options case insensitive

[rascasoft]

Today there's a difference if we do:

> curl -s http://127.0.0.1:8089/query?kind=deployment | jq
{
  "size": 20,
  "count": 0,
  "page": 1,
  "result": []
}

instead of:

> curl -s http://127.0.0.1:8089/query?kind=Deployment | jq
{
  "size": 20,
  "count": 20,
  "page": 1,
  "result": [
    {
      "id": 1,
      "name": "controller",
      "namespace": "metallb-system",
      "kind": "Deployment",
      "issue": "missing_liveness_probe",
      "issue_metadata": null,
      "tool": "vessel.tools.linter",
      "current": true,
      "created_at": "2021-12-27 16:23"
    },
...
...
  ]
}

Since we're talking about urls case should not be relevant.