Add newResultsCommitment, newSpentVoiceCreditsCommitment, newPerVOSpentVoiceCreditsCommitment to the tally output file

[yuetloo]

It looks like from the comment of Poll.verifyTallyResult() here, newResultsCommitment, newSpentVoiceCreditsCommitment, newPerVOSpentVoiceCreditsCommitment will be need to verify tally output data on chain.

Including the fields in the tally output file (tally.json) will save web application the work to calculate these values when submitting the tally data on chain for verification.

The genProof command already calculates these values here (https://github.com/privacy-scaling-explorations/maci/blob/master/cli/ts/genProofs.ts#L549-L572). Just need to write them out to the tally file.

Here's a sample tally.json generated from the genProof command.

{
    "provider": "http://localhost:8545",
    "maci": "0xAF68B245Ec82A1443fC4100BFB020C34e0361F7E",
    "pollId": 0,
    "newTallyCommitment": "0x1dc2362bdef5fd7e5fa7d2fec1cb9846444bdaf750f0490b2780ddf644379102",
    "results": {
        "tally": [
            "15",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0"
        ],
        "salt": "0x19a2ab58158161384b0eabafce6b3d188056f215c83c1534d00158875901ac5e"
    },
    "totalSpentVoiceCredits": {
        "spent": "15",
        "salt": "0x5abd6f3a1d9ec435564a97c80f439e4409ef95fe80380d4db2a98a10633542f"
    },
    "perVOSpentVoiceCredits": {
        "tally": [
            "15",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0",
            "0"
        ],
        "salt": "0x2d7076c44b72a8a7e6a4a934709ab420b2902c41b59196ade17cfec47c282273"
    }
}