[FEAT] - Support ConversionWebhooks generated with Kubebuilder

[IvoGoman]

Priority

None

User Story

As a Greenhouse developer, I would like to generate ConversionWebhooks using the Bubebuilder CLI, so that I can easily add migrations between API Versions.

Description

The current project setup does not allow for generating working ConversionWebhooks due to

1. kube-webhook-certgen does not work with CRDs. The .spec.conversion.webhookClientConfig can not be injected.
2. generation of ConversionWebhooks with Kubebuilder CLI does not work with the Project structure changed from default scaffolding

Decision: conversion should be tested with e2e tests. Existing unit tests should only test the most current API versions

Acceptance Criteria

• cert-manager is used in HelmChart to inject certificates for webhookClientConfig in CRDs and Webhooks
• cert-manager is used in e2e tests to inject certificates for webhookClientConfig in CRDs and Webhooks
• greenhouse project is updated to kubebuilder/v4 project structure

Reference Issues

• [FEAT] - Allow selection of single Cluster on PluginPreset #852
• [FEAT] - TeamRoleBinding supports ClusterSelector #737