stronger typing for Networks concept

[ralexstokes]

I started a module to house this here: https://github.com/ralexstokes/ethereum-consensus/blob/main/ethereum-consensus/src/networks.rs

it would be nice to have stronger typing for the networks we support

e.g.

enum Network {
   Mainnet,
   Goerli,
   ...
}

and use this in lieu of the string name in the config (see here: https://github.com/ralexstokes/ethereum-consensus/blob/main/ethereum-consensus/src/state_transition/context.rs#L75 )

we can then also refactor stuff like this: https://github.com/ralexstokes/mev-rs/blob/main/mev-rs/src/network.rs

[chirag-bgh]

I will take this.

[ralexstokes]

@chirag-bgh great! I am basically thinking to move the stuff from the mev-rs code to the networks module here, and then we will need to execute all the accompanying refactors