Support cost-saving deployment

[renatomariscal]

There are 2 deployment methods documented:

Dual This deployment mode is intended for applications where downtime during deployment needs to be as minimal as possible

And

BlueGreen This deployment mode is intended for applications where downtime during deployment needs to be zero

Both keeps 2 clusters, twice as many pods and much resources.

Would be nice to have a 3rd option optimized for cost instead of uptime, where the old cluster is deleted first, freeing the resource.