Allow to set a webhook backend for the audit logs

[Issif]

Feature Request

Allow to set a webhook backend for the control plane audit logs.

Description

The k8s control plane can send its audit logs to a specified webhook endpoint but nothing allow to configure that in Talos for now. See the official [k8s docs](Allow to set a webhook backend for the audit logs) for more details.

We could have a setting like this:

cluster:
  apiServer:
    auditWebhook:
      server: http://${IP}:${PORT}/${PATH}

which results to create the required config file for the control plane:

apiVersion: v1
kind: Config
clusters:
- name: falco
  cluster:
    server: http://${IP}:${PORT}/${PATH}
contexts:
- context:
    cluster: falco
    user: ""
  name: default-context
current-context: default-context
preferences: {}
users: []

My current need is to be able to use the K8s audit logs plugin of Falco with Talos.