BOP-43 Rename the CRD from Cluster to Blueprint

[ranyodh]

Renaming the Cluster CRD to Blueprint.

This is a breaking change. The blueprint files must be updated after this is merged:

• Publish new manifest to public repo: https://github.com/Mirantis/boundless/blob/main/deploy/static/boundless-operator.yaml (copy from here: https://github.com/Mirantis/boundless-operator/blob/main/deploy/static/boundless-operator.yaml)
• Update boundless-cli to use this new manifest and CRD: BOP-43 Fix blueprint specs blueprint-cli#2
• Update other documentation/references