A new CRD property `PreservePoolsOnDelete` has been added to Filesystem(fs) and
Object Store(os) resources in order to increase protection against data loss.
If it is set to `true`, associated pools won't be deleted when the main
resource(fs/os) is deleted. Creating again the deleted fs/os with the same name
will reuse the preserved pools.
Signed-off-by: Juan Miguel Olmo Martínez <jolmomar@redhat.com>