Added attribute exception handling for description field

[be-kate]

Default access to attribute was giving exceptions when accessing the Jira issues without descriptions.
Sample:

{
  "stdout": "",
  "stderr": "Traceback (most recent call last):\n  File \"/opt/stackstorm/st2/lib/python3.8/site-packages/python_runner/python_action_wrapper.py\", line 395, in <module>\n    obj.run()\n  File \"/opt/stackstorm/st2/lib/python3.8/site-packages/python_runner/python_action_wrapper.py\", line 214, in run\n    output = action.run(**self._parameters)\n  File \"/opt/stackstorm/packs.dev/jira/actions/get_issue.py\", line 14, in run\n    result = to_issue_dict(issue=issue, include_comments=include_comments,\n  File \"/opt/stackstorm/packs.dev/jira/actions/lib/formatters.py\", line 36, in to_issue_dict\n    'description': issue.fields.description,\nAttributeError: 'PropertyHolder' object has no attribute 'description'\n",
  "exit_code": 1,
  "result": "None"
}

Fix:
Added verification that attribute exists before accessing it. Result:

{
  "stdout": "",
  "stderr": "",
  "exit_code": 0,
  "result": {
    "id": "1454821",
    "key": "OPS-12345",
    "url": "https://xyz.atlassian.net/browse/OPS-45131",
    "summary": "NodeXYZ - 2025-07-22T15:11:44",
    "description": null,
    "status": "In Progress",
    "priority": null,
    "resolution": null,
    "labels": [],
    "reporter": "Awesome Person",
    "assignee": "Cute Person",
    "created_at": "2025-07-22T11:11:36.176-0400",
    "updated_at": "2025-07-22T19:32:44.932-0400",
    "resolved_at": null
  }
}

[floatingstatic]

Thanks for the contribution! Looks good to me!