insights: remove restriction for global capture groups insights

Created by: coury-clark

Remove the validation that the capture group insight was restricted to set of repos.

{
  "input":{
    "options": {

    },
    "dataSeries": {
      "options": {
        "label": "mylabel123",
        "lineColor": "red"
      },
      "generatedFromCaptureGroups": true,
      "repositoryScope": {
        "repositories": []
      },
      "query": "file:go\\.mod$ go\\s*(\\d\\.\\d+) patterntype:regexp count:all",
      "timeScope": {
        "stepInterval": {
          "unit": "MONTH",
          "value": 6
        }
      }
    },
    "options": {
      "title": "from API global capture group insight"
    }
  }
}

{
  "data": {
    "createLineChartSearchInsight": {
      "view": {
        "id": "aW5zaWdodF92aWV3OiIyM2V2QTdxQlBTT0tVZGc2VVg3U0hqSE1YdTYi"
      }
    }
  }
}