Preparartion for Cadenza 2 Challenge

[groadabike]

There are several things that need to be implemented for CAD2 challenge

• [x] #374
• [x] #375
  • [x] #373
  • [x] #372
    • [x] Dataloader
    • [x] Architecture
    • [x] Training script
  • [x] #377
  • [x] Task 2 - Rebalancing Classical Music
  • [x] Separation model for replication Task 2
    • [x] Dataloader
    • [x] Architecture
    • [x] Training script
  • [x] #390