provider/openstack: LoadBalancer Security Groups (#11074)
provider/openstack: LoadBalancer Security Groups (#11074)

* provider/openstack: LoadBalancer Security Groups

This commit adds the ability to specify security groups on a loadbalancer
resource.

* provider/openstack: LoadBalancer Security Groups Refactor

Moving common security group code into a dedicated function.

haxorof/terraform-provider-openstack,haxorof/terraform-provider-openstack,haxorof/terraform-provider-openstack