Additional IP support for IPLB in Sydney region

[ryanbutterfield]

As an OVHcloud customer using IPLB in the Sydney region I want IPLB to support adding an Additional IP (Failover IP) so that the same load balancer can be used to load balance multiple services that use the same port (eg. LDAP port 389).

For example:

[Main IPLB IP]:389 -> [Server A, Server B, Server C]:389
[Additional IP #1 IPLB IP]:389 -> [Server D, Server E, Server F]:389
[Additional IP #2 IPLB IP]:389 -> [Server G, Server H]:389