refactor: kubebuilder plugin mode vs cobra + kubebuilder scaffolding

[lander2k2]

Prior to the holiday break we discussed whether it was beneficial to remove the kubebuilder plugin model in favor of using the cobra CLI package directly, and simply leveraging the scaffolding methods of kubebuilder rather than the entire plugin model. Things like adding subcommands to subcommands become a difficult task and may limit our flexibility in the future.