refactor: don't use and generate CRD clientsets

[TheSpiritXIII]

Some motivators:

1. The potential need to split webhooks into its own package: the webhook package should not depend on the entire operator. It would be great if we could split types into its own package. Removing this code creates a clear declination of what should go into the types package.
2. Our clientset code generator is deprecated and slow.
3. The controller-runtime client is easier to use on e2e tests.