feat: Separate script for data preprocessing and augmentation using json config files

[tkarab]

• [x] Create branch from #14 after merging #26 first
• [x] move all 'preprocessing_functions' code to preprocessing .py
• [x] #28
• [x] Create 'apply_preprocessing' function which takes the config filename as input and applies all the functions in order (either to the rms rectified db2 data or any raw or not data from db1/db5)
• [x] Make so that it can also be called from main (using run button)
• [x] Do the exact same steps for the augmentation process