qualys_vmdr: Fix package_nested field in asset data stream.

[kcreddy]

Proposed commit message

`package_nested` field is defined nested, but its structure 
makes it behave like an object.

Fix the structure of `package_nested` field to facilitate 
independent queries inside this nested field.

Note

Changed from:

{
  "fixed_version": [
    "1.31-1ubuntu0.1",
    "3.5-5ubuntu2.2"
  ],
  "name": [
    "libmodule-scandeps-perl",
    "needrestart"
  ],
  "version": [
    "1.31-1",
    "3.5-5ubuntu2.1"
  ]
}

Changed to:

[
  {
    "fixed_version": [
      "1.31-1ubuntu0.1"
    ],
    "name": [
      "libmodule-scandeps-perl"
    ],
    "version": [
      "1.31-1"
    ]
  },
  {
    "fixed_version": [
      "3.5-5ubuntu2.2"
    ],
    "name": [
      "needrestart"
    ],
    "version": [
      "3.5-5ubuntu2.1"
    ]
  }
]

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.
• I have verified that any added dashboard complies with Kibana's Dashboard good practices

How to test this PR locally

1. Pipeline tests pass and updates the structure of package_nested field.

   --- Test results for package: qualys_vmdr - START ---
   ╭─────────────┬──────────────────────┬───────────┬──────────────────────────────────────────────────────────┬────────┬──────────────╮
   │ PACKAGE     │ DATA STREAM          │ TEST TYPE │ TEST NAME                                                │ RESULT │ TIME ELAPSED │
   ├─────────────┼──────────────────────┼───────────┼──────────────────────────────────────────────────────────┼────────┼──────────────┤
   │ qualys_vmdr │ asset_host_detection │ pipeline  │ (ingest pipeline warnings test-asset-host-detection.log) │ PASS   │ 418.355666ms │
   │ qualys_vmdr │ asset_host_detection │ pipeline  │ test-asset-host-detection.log                            │ PASS   │  189.83525ms │
   │ qualys_vmdr │ knowledge_base       │ pipeline  │ (ingest pipeline warnings test-knowledge-base.log)       │ PASS   │ 446.878458ms │
   │ qualys_vmdr │ knowledge_base       │ pipeline  │ test-knowledge-base.log                                  │ PASS   │  91.217833ms │
   │ qualys_vmdr │ user_activity        │ pipeline  │ (ingest pipeline warnings test-no-preserve-custom.log)   │ PASS   │ 393.542042ms │
   │ qualys_vmdr │ user_activity        │ pipeline  │ (ingest pipeline warnings test-yes-preserve-custom.log)  │ PASS   │ 401.810667ms │
   │ qualys_vmdr │ user_activity        │ pipeline  │ test-no-preserve-custom.log                              │ PASS   │  53.487792ms │
   │ qualys_vmdr │ user_activity        │ pipeline  │ test-yes-preserve-custom.log                             │ PASS   │  97.150375ms │
   ╰─────────────┴──────────────────────┴───────────┴──────────────────────────────────────────────────────────┴────────┴──────────────╯
   --- Test results for package: qualys_vmdr - END   ---
   Done
   

2. Verified that field structure update doesn't cause mapping conflict.

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[elastic-vault-github-plugin-prod]

🚀 Benchmarks report

To see the full report comment with /test benchmark fullreport

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 4aad3f0

cc @kcreddy

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube