[Loggers] Logging compatibility

[matteobettini]

This PR introduces loggers for experiments.

Logging

BenchMARL is compatible with the TorchRL loggers.
A list of logger names can be provided in the experiment config.
Example of available options are: wandb, csv, mflow, tensorboard or any other option available in TorchRL. You can specify the loggers
in the yaml config files or in the script arguments like so:

python hydra_run.py "experiment.loggers=[wandb]"

Additionally, you can specify a create_json argument which instructs the trainer to output a .json file in the
format specified by marl-eval.