feat(webhook): Log all admission requests of CRDs

[uwe-mayer]

Description

This PR adds logging to all CREATE, UPDATE, DELETE operations on Greenhouse CRDs.
This is the first step to fix #415 without having access to api server audit logs.

Example log for DELETE on organization:

2024-08-21T13:53:51+02:00	INFO	AdmissionRequest	{"Request": {"uid":"22a2b441-a966-46e2-aa30-1b39ceb5d6ca","kind":{"group":"greenhouse.sap","version":"v1alpha1","kind":"Organization"},"resource":{"group":"greenhouse.sap","version":"v1alpha1","resource":"organizations"},"requestKind":{"group":"greenhouse.sap","version":"v1alpha1","kind":"Organization"},"requestResource":{"group":"greenhouse.sap","version":"v1alpha1","resource":"organizations"},"name":"test-org","operation":"DELETE","userInfo":{"username":"admin","groups":["system:masters","system:authenticated"]},"object":null,"oldObject":{"apiVersion":"greenhouse.sap/v1alpha1","kind":"Organization","metadata":{"annotations":{"kubectl.kubernetes.io/last-applied-configuration":"{\"apiVersion\":\"greenhouse.sap/v1alpha1\",\"kind\":\"Organization\",\"metadata\":{\"annotations\":{},\"name\":\"test-org\"},\"spec\":{\"description\":\"Test organization\",\"mappedOrgAdminIdPGroup\":\"TEST_ORG_ADMIN\"}}\n"},"creationTimestamp":"2024-08-21T11:53:31Z","generation":1,"managedFields":[{"apiVersion":"greenhouse.sap/v1alpha1","fieldsType":"FieldsV1","fieldsV1":{"f:metadata":{"f:annotations":{".":{},"f:kubectl.kubernetes.io/last-applied-configuration":{}}},"f:spec":{".":{},"f:description":{},"f:mappedOrgAdminIdPGroup":{}}},"manager":"kubectl-client-side-apply","operation":"Update","time":"2024-08-21T11:53:31Z"}],"name":"test-org","resourceVersion":"270","uid":"f02101f3-16a6-4c9b-85a0-6e08410e3b33"},"spec":{"description":"Test organization","displayName":"test org","mappedOrgAdminIdPGroup":"TEST_ORG_ADMIN"}},"dryRun":false,"options":{"kind":"DeleteOptions","apiVersion":"meta.k8s.io/v1","propagationPolicy":"Background"}}}

What type of PR is this? (check all applicable)

• 🍕 Feature
• 🐛 Bug Fix
• 📝 Documentation Update
• 🎨 Style
• 🧑‍💻 Code Refactor
• 🔥 Performance Improvements
• ✅ Test
• 🤖 Build
• 🔁 CI
• 📦 Chore (Release)
• ⏩ Revert

Related Tickets & Documents

• Related Issue # [FEAT] - Audit Log forwarding for central cluster audit logs #415