As a LokiStack administrator, I want to declare a reference to a ConfigMap holding the custom Certificate Authority bundle when selecting the swift object storage type, so that I can verify the validity of Swift server side certificates in on premise clusters.

Acceptance Criteria

1. The LokiStack administrator can select a ConfigMap in the same namespace as the LokiStack custom resource that holds the swift object storage CA bundle.
2. The CA Bundle is mounted and used by per Loki container accessing the swift object storage.

Developer Notes

1. The LokiStack custom resource currently allows to reference a ConfigMap in the same namespace for any object storage type. No need to extend the API.
2. The LokiStack createOrUpdate handler does not mount the custom CA bundle ConfigMap for any other store than S3: https://github.com/grafana/loki/blob/main/operator/internal/manifests/storage/configure.go#L34-L38