[FEAT] - label propagation: allow wildcards

[uwe-mayer]

Priority

None

User Story

As a Cluster-admin I want to make sure all metadata get's automatically propagated from shoot --> secret --> cluster

Description

Currently to propagatae metadata labels from Secret to Cluster we need to spec the following annotation on the Secret:

annotations:
    "greenhouse.sap/propagate-labels": "metadata.greenhouse.sap/<key-1>,metadata.greenhouse.sap/<key-2>"

Ideally we could just propagate metadata.greenhouse.sap/* making sure that we only have to label the source to have the new data on the target.

Also it would be ideal if we can reuse Greenhouse core label propagation in shoot-grafter label propagation. For this we would need to make our library public.
First step is to move the propagator code under /pkg/lifecycle

Acceptance Criteria

• We can use wildcards for label propagation
• Greenhouse label propagation can be consumed by downstream

Reference Issues

No response