Serialize config with BigInts

e.g. for:

export default createConfig({
  networks: {
    mainnet: { chainId: 1, transport: http(process.env.PONDER_RPC_URL_MAINNET) },
  },
  contracts: {
    'FooToken': {
      abi: ERC721,
      address: "0x1231231231231231231231231231231231231231",
      network: "mainnet",
      startBlock: 11111111,
      filter: {
        event: "Transfer",
        args: {
          tokenId: [1n, 2n, 3n],
        },
      },
    },
  },
})

ponder-sh / ponder

Serialize config with BigInts #1050