metal chart deployment can fail when resources are not overriden

[Gerrit91]

When metal_set_resource_limits is enabled and neither metal_api_resources nor metal_masterdata_api_resources nor metal_console_resources are overriden, the deployment fails with:

    Error: template: metal-control-plane/templates/metal-console.yaml:41:17: executing "metal-control-plane/templates/metal-console.yaml" at <.Values.resources.metal_console>: nil pointer evaluating interface {}.metal_console

We probably cannot define resources: when we do not have any overrides...