Bootstrap the Mutating Webhook

[thisthat]

Technical Details

The operator of #2 is extended with the registration of a Mutating Webhook in the Admission Controller.
A reference implementation can be found here:
https://github.com/open-feature/open-feature-operator/blob/7d099c7b72f9a7430581696218458eaee31fb0df/main.go#L90-L98

Acceptance Criteria

• A Mutating Webhook is registered.
• Annotations of the resource are logged at each request.
• All requests are always allowed.

DoD

• A Mutating Webhook is registered in the Admission Controller.
• The operator is extended with the Webhook implementation

Dependencies

• Bootstrap the Keptn Lifecycle Operator #2

Resources

• https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/
• https://github.com/open-feature/open-feature-operator
• https://book.kubebuilder.io/reference/webhook-for-core-types.html