+++ This bug was initially created as a clone of Bug #1813559 +++

There are use-cases where a load balancer should have multiple VIP addresses allocated from the same Neutron network. Users can specify additional subnet_id/ip_address pairs to bring upon the VIP port. This will allow for situations like having an LB with both IPv4+IPv6 or being exposed to both public and private subnets.

This would extend the load balancer API to support it. Example:

"additional_vips": [

,
]

https://storyboard.openstack.org/#!/story/2005608
https://review.opendev.org/#/q/%22Story:+2005608%22

Note: This BZ is specific to the ovn-octavia-provider

Acceptance criteria:

1. Successful Creation of a Load Balancer with Multiple VIPs
2. Correct Traffic Distribution Across Multiple VIPs
3. Dynamically Adding a VIP to an Existing Load Balancer  <<<No longer part of Acceptance criteria, VIP must be added/removed during creation
4. Dynamically Removing a VIP from an Existing Load Balancer <<<No longer part of Acceptance criteria, VIP must be added/removed during creation
5. Deletion of a Load Balancer with Multiple VIPs
6. Error Handling for Duplicate VIP Assignment
7. Error Handling for VIPs from Different Networks