Add support for reconciling Gateway Listeners

[maleck13]

What

The gateway controller in the traffic controller, will need to reconcile the listeners defined in the gateway. For each listener the following requirements have been identified

• Check if the host is part of a managed zone for that tenant
• If not then it can be ignored
• ensure there is a certificate for the host specified (if it is a wildcard host the cert should be a wildcard cert)
• ensure there is a DNSRecord based on the LB status in the gateway (only once the certificate is ready)

[david-martin]

@maleck13 is this different from #53

[maleck13]

No but I guess this one has more info? so close 53?

[david-martin]

Agreed