Allow "late-binding" for the IP-address to use as VIP-address.

[tedlean]

Currently the IP-address in the Vip CR is required and immutable.
This means that the VIP-address cannot be changed or added later in the deployments process.
You would have to create a new Vip CO having a new name. This would again mean that Flow and Gateway COs
need to be updated to refer this new Vip CO.
In fact, it could ripple all the way to the target application, that also might need to know the VIP-addresses.

If should be possible to prepare the complete CO configuration as part of system integration.
The Vip CO should be seen as a "placeholder" to be filled with a site-specific VIP-address later at deployment time.
Thus the Vip CR should be changed to not require an immutable IP-address as part of the CO creation.

Over time it even might be that the VIP-address is not configured but revealed by DNS or other means.