Add test debug codeLens

[ikbendewilliam]

{
    "name": "Run w/",
    "type": "dart",
    "request": "launch",
    "runTestsOnDevice": true,
    "cwd": ".",
    "codeLens": {
        "for": [
            "debug-test-file",
        ],
        "title": "${debugType} on device"
    }
}

And then you can use the "Debug on device" button to start fixing/adding your tests. I always use the macos device to run, but it can be anything.