ESDs: Allow HTTP to HTTPS redirect via AS3 instead of iRule

[BenjaminLudwigSAP]

The ESD just needs to have 'redirect80' set to true and it will be set accordingly in the HTTPS service AS3 object.

When this is merged we can test in QA simply by temporarily changing the ESD in the Octavia configuration configmap.

Closes #119

[notandy]

Nice short PR, but I it's a bit more complicated:
Users set their redirect_to_http ESD flag in their port 80 listener, which is a SERVICE_HTTP, so this AS3 flag is ignored.
We need to find out which HTTPS listener (443) is related, set the redirect80 flag and (probably, need to be tested) omit the Port 80 AS3 service_http completely.