cmd/k8s-operator,k8s-operator,kube: Add TSRecorder CRD + controller (#13299)

cmd/k8s-operator,k8s-operator,kube: Add TSRecorder CRD + controller

Deploys tsrecorder images to the operator's cluster. S3 storage is
configured via environment variables from a k8s Secret. Currently
only supports a single tsrecorder replica, but I've tried to take early
steps towards supporting multiple replicas by e.g. having a separate
secret for auth and state storage.

Example CR:

```yaml
apiVersion: tailscale.com/v1alpha1
kind: Recorder
metadata:
  name: rec
spec:
  enableUI: true
```

Updates #13298

Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>

cmd/k8s-operator/deploy/crds/tailscale.com_dnsconfigs.yaml

@@ -89,14 +89,14 @@ spec:
                   type: object
                   properties:
                     image:
-                      description: Nameserver image.
+                      description: Nameserver image. Defaults to tailscale/k8s-nameserver:unstable.
                       type: object
                       properties:
                         repo:
                           description: Repo defaults to tailscale/k8s-nameserver.
                           type: string
                         tag:
-                          description: Tag defaults to operator's own tag.
+                          description: Tag defaults to unstable.
                           type: string
             status:
               description: |-