websocket machine.list parent group label should return hostname

[Peter Makowski]

machine.list group by parent label should return a parent's hostname instead of system id

Request:
{"method":"machine.list","type":0,"params":{"filter":{},"group_collapsed":[],"group_key":"parent","page_number":1,"page_size":50,"sort_direction":"descending","sort_key":"hostname"},"request_id":25}

Current:

{"type": 1, "request_id": 23, "rtype": 0, "result": {"count": 9, "cur_page": 1, "num_pages": 1, "groups": [{"name": "knpge8", "value": "knpge8", "count": 9, "collapsed": false, "items": []}}

Expected:

{"type": 1, "request_id": 23, "rtype": 0, "result": {"count": 9, "cur_page": 1, "num_pages": 1, "groups": [{"name": "bolla", "value": "knpge8", "count": 9, "collapsed": false, "items": []}}

[Peter Makowski (petermakowski)]

We do not necessarily need the returned value to be system_id, it can be the hostname for both label and value if that makes it easier.