Improve shortDescription in SARIF reports

[candrews]

SARIF allows a "shortDescription" to be provided:

The shortDescription property SHOULD be a single sentence that is understandable when visible space is limited to a single line of text.

See:
https://docs.oasis-open.org/sarif/sarif/v2.1.0/os/sarif-v2.1.0-os.html#_Toc34317845

Currently, Trivy set the shortDescription to the id of the vulnerability, which is not very readable or understandable.

For example:

{
  "id": "CVE-2020-13844",
  "name": "OsPackageVulnerability",
  "shortDescription": {
    "text": "CVE-2020-13844"
  },
  "fullDescription": {
    "text": "Arm Armv8-A core implementations utilizing speculative execution past unconditional changes in control flow may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka \u0026#34;straight-line speculation.\u0026#34;"
  },
  "defaultConfiguration": {
    "level": "warning"
  },
  "helpUri": "https://avd.aquasec.com/nvd/cve-2020-13844",
  "help": {
    "text": "Vulnerability CVE-2020-13844\nSeverity: MEDIUM\nPackage: libstdc++6\nFixed Version: \nLink: [CVE-2020-13844](https://avd.aquasec.com/nvd/cve-2020-13844)\nArm Armv8-A core implementations utilizing speculative execution past unconditional changes in control flow may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka \"straight-line speculation.\"",
    "markdown": "**Vulnerability CVE-2020-13844**\n| Severity | Package | Fixed Version | Link |\n| --- | --- | --- | --- |\n|MEDIUM|libstdc++6||[CVE-2020-13844](https://avd.aquasec.com/nvd/cve-2020-13844)|\n\nArm Armv8-A core implementations utilizing speculative execution past unconditional changes in control flow may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka \"straight-line speculation.\""
  },
  "properties": {
    "precision": "very-high",
    "security-severity": "5.5",
    "tags": [
      "vulnerability",
      "security",
      "MEDIUM"
    ]
  }
}

A shortDescription of CVE-2020-13844 isn't "understandable"

I suggest the vulnerability "title" be used instead, which in this case, would be kernel: ARM straight-line speculation vulnerability