[onert/train] Support Integration Tests for training

[YongseopKim]

Let's support Integration Tests for training.

• circle model -> train -> compare with tf model

To get it, we have to clarify

1. How to validate? How to realize the model is trained?
   • Fixed/Static random seed and golden data?
2. How many time to test? Training takes much more cost than inference.

/cc @Samsung/one_onert