Separate out code for EVM network substate

[ehildenb]

Perhaps we could achieve cleaner separation of all the files by pulling out the subconfiguration for the network into its own file.

We would add an extra cell, networkCommands, which is used to communicate between the two configurations. It would only deal with looking up/retrieving network data. Operators like #newAccount and the like would be defined there, and the various loaders/checkers could be as well.

Long term this would help with factoring out the network semantics from the KEVM, KIELE, and KWASM semantics so that they share a modular blockchain semantics.

@dwightguth ?