[ML][Training] Updating code to native API changes

[ML][Training] Updating code to native API changes

Native C++ API cannot be used so this commit removes
all dependencies on ccapi-machine-learning-training
library and C++ headers.

Functions and objects that were using C++ objects
ported to C handlers and functions.

[Verification] Code compiles without errors and tizen.ml is available

Change-Id: Icb18546ab1a72f729b9405f736e5c270ad0be3a8