[FEATURE] More flexible networks

[sash-a]

We recently got a PR #1099 to add the ability to chain torso's together. This would greatly increase the flexibility of creating the networks through config.

The goal would be for the main network class to look something like this:

class Network(nn.Module)
    torso: CompositeNetwork
    head: nn.Module

    def __call__(x, ...):
        x = do some stuff to the input  # each different network would do different stuff e.g centralized/decentralized etc
        return head(torso(x))

Then torsos and head can be defined easily through config and chained through the CompositeNetwork a similar system exists in stoix, which this change is inspired by.