Missing UniqueFields key in AdoFields notification config is not handled.

[nharper285]

Information

• Onefuzz version: 7.0.0

Provide detailed reproduction steps (if any)

1. Create notification config.json file with list of UniqueFields that are not present in AdoFields.
   Ex.

{
    "config": {
        "base_url": "https://dev.azure.com/fuzzfuzz",
        "type": "Bug",
        "project": "Onefuzz",
        "ado_fields": {
            "System.AreaPath": "Onefuzz",
            "Microsoft.VSTS.Scheduling.StoryPoints": "1",
            "System.Title": "[C#ANARY - TESTING STUFF] {{ report.crash_site }} - {{ report.executable }}",
            "Microsoft.VSTS.TCM.ReproSteps": "This is my call stack: <ul> {% for item in report.call_stack %} <li> {{ item }} </li> {% endfor %} </ul>"
        },
        "comment": "This is my comment. {{ report.input_sha256 }} {{ input_url }} <br> <pre>{{ repro_cmd }}</pre>",
        "unique_fields": [
            **"Microsoft.VSTS.Common.CustomString01",
            "Microsoft.VSTS.Common.CustomString02",
            "Microsoft.VSTS.Common.CustomString03",**
            "System.Title",
            "System.AreaPath"
        ],
        "on_duplicate": {
            "comment": "Another <a href='{{ input_url }}'>POC</a> was found in <a href='{{ target_url }}'>target</a>. <br> <pre>{{ repro_cmd }}</pre>",
            "set_state": {
                "Resolved": "Active"
            },
            "ado_fields": {},
            "increment": [
                "Microsoft.VSTS.Scheduling.StoryPoints"
            ]
        }
    }
}

Expected result

What is the expected result of the above steps?
Ado bugs are properly filed.

Actual result

What is the actual result of the above steps?
Bugs are not filed.

AB#45444