[ Mixed Tensor ] add tensor type property in initContext

[ Mixed Tensor ] add tensor type property in initContext

This PR add the tensor type (Format, Weight Tensor DataType,
Activation Tensor DataType) in initContext.
- Remove the tensor type variables and setter, getter member function
in layer, layer_devel, loss layer etc.
- add tensor type setter in initContext
- set the var_grad ( input & ouput ) Tensor Type according to model
Tensor Data Type.
- Add ModelTensorTypeInfo : eg. FP16_FP16 ( Weight FP16, Activation
FP16 )

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: jijoong.moon <jijoong.moon@samsung.com>