mv_machine_learning: code refactoring

mv_machine_learning: code refactoring

[Version] : 0.23.2-0
[Issue type] : code refactoring

Did code refactoring like below,
	- Move ConfigureBackendType function to Inference class and do not
	  keep the backend type in Inference class. Instead, pass the backend
	  type through Bind function directly.
	- Rename ConfigureBackendType to CheckBackendType. Now this function
	  checks if a given backend type is valid or not when Bind function
	  is called.
	- Add some exception code.

This is just a step for next code refactoring.

Change-Id: Id81ba442656823540c45be00bc398d961662b6b0
Signed-off-by: Inki Dae <inki.dae@samsung.com>