impose test format verification after fill

[winsvega]

looks like evmone-t8n generated genesis with "baseFeePerGas": "0x00", on frontier network

so we need to check the generated test format with consume. like I did with retesteth. if blockchain test is of network frontier. the genesis must not have other fork fields
and vice versa. this is not being checked. I am getting test with genesis header with baseFeePerGas when using evmonet8n

[danceratopz]

Currently evmone's t8n returns invalid block header fields for Frontier (to be double-checked by @winsvega) - this is blocking #808.

[winsvega]

ethereum/evmone#1073