As a dev, I want to implement the namespace-scoped PodPlacementConfig CRD API as described in https://github.com/openshift/multiarch-tuning-operator/blob/main/docs/enhancements/MTO-0002-local-pod-placement.md#namespace-scoped-podplacementconfig-crd.

Acceptance criteria:

• The new CRD is defined and available as golang types and manifests based on
• The CRD v1beta1 is set as hub for multi-version definitions and the related webhook is created
• The webhook is also set as a validating webhook (we don't need to implement validation rules for this story)
• Unit tests are implemented for each new function that does not depend on external services communication
• Integration tests are implemented to validate the API fields constraints set through kubebuilder annotations
• some E2E cases implemented to test the creation/deletion/updates of the object with OCP