Refactor the way to select renderer

Instead of using other criteria than those used for PCE (to make the decision between optical pce and otn pce), reuse the service-type from common module (and already used by pce) to choose adequate renderer (optical vs otn).
Perform some refactoring to update transportpce-device-renderer model by:

• replacing service-type (which is confusing) in otn-renderer api by service-format which is more appropriate
• changing service-rate type to be aligned with service-create rpc input