Add client re-generation in options flow

[ufozone]

Related to #89

[ufozone]

Delete old HA key from robot

{
    "cmd": {
        "command": "attribute.delete",
        "params": {
            "imei": "35000000000",
            "key": "robot_clientX",
            "startTs": "1000-01-01T00:00:00Z",
            "endTs": "3000-12-31T23:59:59Z"
        }
    }
}