[occm] Support backend re-encryption

/kind feature

What happened:
Currently, when creating a LoadBalancer with the annotations "loadbalancer.openstack.org/x-forwarded-for" and "loadbalancer.openstack.org/default-tls-container-ref" the connection between the LB and the K8S Worker Node is not encrypted, and encryption cannot be enabled (no annotations or other configuration method are available).

--enable-tls

What you expected to happen:
I wanted to be able to enable encryption for the connection between the LoadBalancer and the K8S Worker Node via an annotation. This can be done manually by setting the "--enable-tls" parameter for the LoadBalancer pool created by OCCM.

How to reproduce it:

1. Create LoadBalancer service using below annotations:
   loadbalancer.openstack.org/x-forwarded-for: "true"
   loadbalancer.openstack.org/default-tls-container-ref: "..."
2. Set "--enable-tls" for LoadBalancer HTTPS listener's pool created by OCCM

Anything else we need to know?:
Docs describing how to create LB with backend re-encryption
https://docs.openstack.org/octavia/latest/user/guides/basic-cookbook.html#deploy-a-http-2-load-balancer-with-alpn-tls-extension-and-backend-re-encryption

Environment:

• openstack-cloud-controller-manager(or other related binary) version: v1.34.1
• OpenStack version: 2024.01

Start by tracing OCCM's LoadBalancer handling for the x-forwarded-for and default-tls-container-ref annotations, focusing on the HTTPS listener pool and its --enable-tls setting. Compare the expected behavior with the linked Octavia backend re-encryption cookbook. Done means a LoadBalancer annotation or configuration enables encryption between the LoadBalancer and Kubernetes worker node, with the relevant behavior tested.