Add support for new OCCM cloud provider options

[kayrus]

In order to enable PROXY protocol workaround for local k8s traffic kubernikus needs to support enable-ingress-hostname and ingress-hostname-suffix options.

PROXY protocol listeners always expect a PROXY header, while k8s pods traffic to external LB IP is explicitly routed through k8s network, which causes service to be unavailable from k8s. The workaround avoids this and traffic comes through the LB public IP that adds the required PROXY header.

see also gardener/gardener-extension-provider-openstack#577

cc @databus23 @BugRoger