Fixed Chargeback Rate display

Fixed code to display of Cloud/Infrastructure providers rates after Save
Code fix properly identifies any EMS as such
Refactored code for better readability

Linked similar GitHub issue to the BZ ticket

https://bugzilla.redhat.com/show_bug.cgi?id=1073083
https://github.com/ManageIQ/manageiq/issues/138#event-148990147
@jrafanie I think that `chargeback_show_typ` (why not `chargeback_show_type`?) is a hash key used in the UI.  Not sure why the model would care about any of this.