[HC] Create and expose 2 new endpoints

[sanzmauro]

Split Synchronizer

What did you accomplish?

http://localhost:3010/health/application

{
  "healthy": true,
  "healthySince": "2021-09-30T10:44:35.627427-03:00",
  "items": [
    {
      "name": "Splits",
      "healthy": true,
      "lastHit": "2021-09-30T10:44:37.44238-03:00"
    },
    {
      "name": "Segments",
      "healthy": true,
      "lastHit": "2021-09-30T10:44:37.493244-03:00"
    },
    {
      "name": "Storage",
      "healthy": true
    }
  ]
}

http://localhost:3010/health/services

{
  "serviceStatus": "healthy",
  "dependencies": [
    {
      "service": "https://telemetry.split-stage.io/version",
      "healthy": true,
      "healthySince": "2021-09-30T10:44:35.627487-03:00"
    },
    {
      "service": "https://auth.split-stage.io/version",
      "healthy": true,
      "healthySince": "2021-09-30T10:44:35.627498-03:00"
    },
    {
      "service": "https://sdk.split-stage.io/api/version",
      "healthy": true,
      "healthySince": "2021-09-30T10:44:35.627501-03:00"
    },
    {
      "service": "https://events.split-stage.io/api/version",
      "healthy": true,
      "healthySince": "2021-09-30T10:44:35.627504-03:00"
    },
    {
      "service": "https://streaming.split.io/health",
      "healthy": true,
      "healthySince": "2021-09-30T10:44:35.627506-03:00"
    }
  ]
}