Hydra ML config manager instead of Argparse

[mauriciogtec]

Use Hydra instead of Argparse, since it is easier to manage configs of different models, datasets, etc.

For example, iinstead of instantiating models with lengthy code, such as:

if args.model == "....":
   model = ....

We can use a single call

model = instantiate(cfg.model)

[mauriciogtec]

currently used by the etnn_spatial

[audiracmichelle]

Closed in 77bf3ba