Add adds a new Controller to mgr with r as the reconcile.Reconciler.

Params are params to create and manage the webhook resources (Cert secret and ValidatingWebhookConfiguration).

ReconcileWebhookResources reconciles the certificates used by the webhook server.

WebhookCertificates holds the artifacts used by the webhook server and the webhook configuration.

AdmissionControllerInterface helps to setup webhooks for different versions of the admissionregistration API.