Add an option to override scan options (LOG_LEVEL for example).

[isamauny]

Ability to override scan engine runtime options via a JSON structure:

        "logLevel": "debug",
        "logDestination": "stdout+platform",
        "maxLogFileSize": 2147483648,
        "headerNameRequestId": "x-scan-request-id",
        "headerNameScenarioId": "x-scan-scenario-id",
        "flowrate": 10,
        "timeout": 30,
        "followRedirection": true,
        "happyPathRetry": 1,
        "happyPathOnly": false,
        "maxScanTime": 3600,
        "memoryLimit": 2147483648,
        "memoryTimeSpan": 10,
        "indexed": false,
        "prettify": false,
        "maxBodySizeScan": 10485760,
        "maxHttpResponseSizeHappyPathReport": 0,
        "maxBodySizeHappyPathReport": 8092,
        "maxHttpResponseSizeTestReport": 0,
        "maxBodySizeTestReport": 8092,
        "errorsOnly": true,
        "maxIssues": 10000,
        "maxReportSize": 104857600