Make rest monitor config in chart mergeable

[xin-hedera]

Description:

This PR makes the rest monitor config in chart mergable

• Change rest monitor config to use yaml syntax
• Change the default values and secret template accordingly

Related issue(s):

Fixes #8657

Notes for reviewer:

This is the output:

$ helm template  -s templates/monitor/secret.yaml --set monitor.config.stateproof.enabled=false  mirror hedera-mirror-rest
---
# Source: hedera-mirror-rest/templates/monitor/secret.yaml
apiVersion: v1
kind: Secret
metadata:
  labels:
    app.kubernetes.io/component: rest-monitor
    app.kubernetes.io/name: hedera-mirror-rest-monitor
    app.kubernetes.io/instance: mirror
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/part-of: hedera-mirror-node
    app.kubernetes.io/version: "0.109.0-SNAPSHOT"
    helm.sh/chart: hedera-mirror-rest-0.109.0-SNAPSHOT
  name: mirror-hedera-mirror-rest-monitor
  namespace: mainnet
type: Opaque
stringData:
  serverlist.json: |
    {
      "servers": [
        {
          "baseUrl": "http://mirror-rest:80",
          "name": "kubernetes",
          "restJavaUrl": "http://mirror-restjava:80",
          "web3Url": "http://mirror-web3:80"
        }
      ],
      "stateproof": {
        "enabled": false
      }
    }

Checklist

• [ ] Documented (Code comments, README, etc.)
• [x] Tested (unit, integration, etc.)

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 92.12%. Comparing base (f2774e4) to head (70ade4d).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8658 +/- ## ========================================= Coverage 92.11% 92.12% Complexity 7541 7541 ========================================= Files 920 920 Lines 30066 30066 Branches 3659 3659 ========================================= + Hits 27696 27699 +3 + Misses 1547 1544 -3 Partials 823 823 ```

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