REF: Refactor transformation, training and pipeline under cacheable

[schobbejak]

Currently there are two folders for training and transformation that implement 4 classes:

• TrainingPipeline < Training.py
• TransformationPipeline < Transforming.py
• TrainingBlock < Training_block.py
• TransformingBlock < Transformation_block.py

Refactor so it falls under one folder 'cacheable'

• CTrainingPipeline
• CTransformPipeline
• CTrainingBlock
• CTransformBlock