Description

As a node operator, I would like Besu to be able to parse configs in the same way as other clients, so interoperability testing and multi-client network operation is simpler.

By default, Besu should use the same format as Geth for a genesis file.
With a command line option (suggestion: --genesis-style=Besu?) the prior, Besu specific and optimized format should still be supported, for the known edge case requiring very large genesis state.