Generate a verifier.sol file for the chunked zkey

[Divide-By-0]

Currently, we load the zkey in chunks to ensure that we can actually fit it into memory. However, there is no verifier.sol generated. So, we either need to fork snarkjs to generate a verifier.sol from the chunked zkeys, or also output a raw zkey that corresponds to the same chunked zkey, that we can call the normal snarkjs verifier generation from.

[Divide-By-0]

Done with https://github.com/zk-email-verify/zk-email-verify/blob/main/dizkus-scripts/3_gen_both_zkeys.sh