Add PyTorch Baselines

[jcformanek]

PyTorch is most widely used by other researchers in the Offline MARL field. Adding PyTorch implementations for some of the baselines should improve the adoption of the baselines.

High Priority Baselines

• IDDPG+BC
• IDQN+CQL

[jcformanek]

Added IDDPG+BC and IQL+CQL. Need to still properly benchmark them.