RBMC: Handle Status/Health for manager

[jeaaustx]

The Status/Health of the Redundancy property of the Manager response should reflect the current state. When redundancy is enabled and failovers are allowed the Health should reflect OK. When redundancy is not enabled or not allowed the Health should indicate Warning.

Tested:

• Redfish service validator passes for Managers

Note: Tested on both active and passive BMC. Mode and Status for
Redundancy are the same on each in each scenario.

/* Redundancy is enabled and allowed */
curl -k -H "X-Auth-Token: $token" -H "Content-Type: application/json" https://${BMC_IP}/redfish/v1/Managers/bmc
{
  [...]
    "Redundancy": [
    {
[...]
      "Mode": "Failover",
[...]
      "Status": {
        "Health": "OK",
        "State": "Enabled"

      }
    }
  ],
  "Redundancy@odata.count": 1,
[...]

/* Redundancy is disabled */
curl -k -H "X-Auth-Token: $token" -H "Content-Type: application/json" https://${BMC_IP}/redfish/v1/Managers/bmc
{
  [...]
    "Redundancy": [
    {
[...]
      "Mode": "NotRedundant",
[...]
      "Status": {
        "Health": "Warning",
        "State": "Disabled"
      }
    }
  ],
  "Redundancy@odata.count": 1,
[...]

/* Redundancy is enabled but not allowed */
curl -k -H "X-Auth-Token: $token" -H "Content-Type: application/json" https://${BMC_IP}/redfish/v1/Managers/bmc
{
  [...]
    "Redundancy": [
    {
[...]
      "Mode": "Failover",
[...]
      "Status": {
        "Health": "Warning",
        "State": "Disabled"
      }
    }
  ],
  "Redundancy@odata.count": 1,
[...]

[jnin-dev]

Beyond what Gunnar stated about the conditional, this looks good to me