Rework Rollout Conditions

[dthomson25]

Currently, there are invalidSpec and available conditions. The invalidSpec condition highlights invalid yaml, but the available condition needs to be fleshed out more. The available condition is not used for the Canary strategy and its use in the BlueGreen strategy does not indicate the status of a rollout well. Instead, the condition indicates that the active service is pointing at a replicaset and that replicaset is at the desired number of replicas. As a result, the rollout could have an available condition set to true while the controller is still working on the rollout.

With the work required to rework the available condition, we will need to make sure that we are able to answer the following questions. What does it mean for a rollout to be available? Does that mean the rollout is in a steady-state? Does that mean the rollout is serving traffic to prod?

[dthomson25]

The Progressing condition was introduced with the implementing ProgessDeadlineSeconds PR (#54) to indicates that a rollout is in a steady-state. The #60 PR improves the available condition to make it more clear when a Rollout is available.

[dthomson25]

Closing with #60 and #54 as the fixes