Feature/cluster id hex

[nikkictl]

What is this change?

Surfaces the hexadecimal cluster id in sensuctl cluster health and sensuctl cluster member-list. Adds the cluster response header to the /health data type and response.

Why is this change necessary?

Closes #2870.

Does your change need a Changelog entry?

Yas.

Do you need clarification on anything?

Nah.

Were there any complications while making this change?

Nah.

Have you reviewed and updated the documentation for this change? Is new documentation required?

sensu/sensu-docs#1390

How did you verify this change?

Updated the following test cases

• https://sensuinc.testrail.io/index.php?/cases/view/149
• https://sensuinc.testrail.io/index.php?/cases/view/151
• https://sensuinc.testrail.io/index.php?/cases/view/3842
• https://sensuinc.testrail.io/index.php?/cases/view/5514

Before:

(release-5.5.1)$ curl http://127.0.0.1:8080/health | jq .
{
  "Alarms": null,
  "ClusterHealth": [
    {
      "MemberID": 9882886658148555000,
      "Name": "default",
      "Err": "",
      "Healthy": true
    }
  ]
}

(release-5.5.1)$ sensuctl cluster health
         ID            Name     Error   Healthy  
 ────────────────── ────────── ─────── ───────── 
  ac6007e1e32e2d19   backend3           true     
  d39305853d0fb740   backend1           true     
  e01784ae8c57bedb   backend2           true     
(release-5.5.1)$ sensuctl cluster member-list
         ID            Name          Peer URLs             Client URLs       
 ────────────────── ────────── ────────────────────── ────────────────────── 
  ac6007e1e32e2d19   backend3   http://backend3:2380   http://backend3:2379  
  d39305853d0fb740   backend1   http://backend1:2380   http://backend1:2379  
  e01784ae8c57bedb   backend2   http://backend2:2380   http://backend2:2379

After:

(release-5.6.0)$ curl http://127.0.0.1:8080/health | jq .
{
  "Alarms": null,
  "ClusterHealth": [
    {
      "MemberID": 9882886658148555000,
      "Name": "default",
      "Err": "",
      "Healthy": true
    }
  ],
  "Header": {
    "cluster_id": 4255616304056077000,
    "member_id": 9882886658148555000,
    "raft_term": 26
  }
}

(release-5.6.0)$ sensuctl cluster health
=== Cluster ID: 11605770c9b38c21
         ID            Name     Error   Healthy  
 ────────────────── ────────── ─────── ───────── 
  ac6007e1e32e2d19   backend3           true     
  d39305853d0fb740   backend1           true     
  e01784ae8c57bedb   backend2           true     
(release-5.6.0)$ sensuctl cluster member-list
=== Cluster ID: 11605770c9b38c21
         ID            Name          Peer URLs             Client URLs       
 ────────────────── ────────── ────────────────────── ────────────────────── 
  ac6007e1e32e2d19   backend3   http://backend3:2380   http://backend3:2379  
  d39305853d0fb740   backend1   http://backend1:2380   http://backend1:2379  
  e01784ae8c57bedb   backend2   http://backend2:2380   http://backend2:2379  

[echlebek]

[palourde]