Add site creation date when creating a site

[zakwatts]

Currently when adding a site via the api, the response is:
Site added successfully: {'client_site_id': 1, 'client_site_name': 'test_site_1', 'orientation': 15.0, 'tilt': 35.0, 'latitude': 53.68, 'longitude': -2.0, 'inverter_capacity_kw': 4.0, 'module_capacity_kw': 4.0, 'site_uuid': '1425036a-4cc6-41e9-982b-112debebfede', 'capacity_kw': 4.0, 'dno': '{"dno_id": "23", "name": "_M", "long_name": "NPG (Yorkshire Electric)"}', 'gsp': '{"gsp_id": "109", "name": "Elland"}'}

It could also be useful to log the date the site was also added

[zakwatts]

@peterdudfield is this something that we already do?

[peterdudfield]

Not currently,

[peterdudfield]

I can add the created_utc time back in the repsonse? Would that be useful?