Add new parameter support for Mercado Pago reclaim verifier to work with brazilian payload data (for Pix integration)

[GalaticStryder]

When we send money via Pix to another user, we get the following response from Mercado Pago:

                  "results": [
                    {
                      "accessibility_text": "-10 reais com 0 centavos",
                      "actions": [],
                      "additionalInfo": null,
                      "amount": {
                        "cents": "00",
                        "cents_text": "",
                        "currency_id": "BRL",
                        "decimal_separator": ",",
                        "fraction": "-10",
                        "strike_through": false,
                        "symbol": "R$",
                        "symbol_text": "Real"
                      },
                      "category": "transfers",
                      "creationDate": "2025-05-07T23:43:44.000Z",
                      "date": "20h43",
                      "description": "Transferência via Pix",
                      "email": null,
                      "entity": "payout",
                      "grouperDate": {
                        "key": "Hoje",
                        "value": "20h43"
                      },
                      "icon": "ic_transfer_fiat",
                      "id": "pix_transfer_mo_payout_movement-78711072109fcc0e6bccfa366e35357cf30e4f8d",
                      "image": null,
                      "initials": null,
                      "lastModified": "2025-05-07T23:44:13.833Z",
                      "link": "/activities/detail/pix_transfer_mo_payout_movement-78711072109fcc0e6bccfa366e35357cf30e4f8d?from=mp-home",
                      "moneyReleaseDate": null,
                      "paymentMethod": {
                        "altText": "Entidade: Mercado Pago",
                        "fallback": "https://http2.mlstatic.com/storage/activities-middle-end/activities-assets/rowfeed/logos-pm/svg/ic_default_bank.svg",
                        "image": "https://http2.mlstatic.com/storage/activities-middle-end/activities-assets/rowfeed/logos-pm/svg/ic_common_account_money_v2.svg",
                        "text": "Saldo em conta"
                      },
                      "status": {
                        "code": "",
                        "color": "",
                        "text": ""
                      },
                      "subCategory": "pix",
                      "title": "Icaro Pereira Hoff",
                      "type": "pix_transfer_mo_payout_movement",
                      "version": 2
                    },
                  ]

Our data shows negative values for sent money, as well as different separator, so I guess we would need to adjust the code to match it:

 * Parses the amount from the proof.
 *
 * @param _amount The amount to parse (fraction part).
 * @param _amountCents The cents amount to parse.
 * @param _decimals The decimals of the token.
 * @param _decimalSeparator The decimal separator character (comma for BRL).
 */
function _parseAmount(
    string memory _amount, 
    string memory _amountCents, 
    uint8 _decimals,
    string memory _decimalSeparator
) internal pure returns(int256) {
    // For BRL, we use 0x2C (comma) as the decimal separator
    uint8 separatorChar = bytes(_decimalSeparator)[0] == 0x2C ? 0x2C : 0x2E; // comma or period
    
    // Handle negative amounts
    bool isNegative = bytes(_amount).length > 0 && bytes(_amount)[0] == 0x2D; // '-' character
    string memory absAmount = isNegative ? _amount.substring(1) : _amount;
    
    uint256 baseAmount = absAmount.stringToUint(
        separatorChar,
        _decimals
    );
    uint256 centsAmount = _amountCents.stringToUint(_decimals - 2);
    uint256 totalAmount = baseAmount + centsAmount;
    
    // Apply negative sign if needed
    return isNegative ? -int256(totalAmount) : int256(totalAmount);
}```

We need to add if clauses for this based on *BRL* or *ARS* as well.

Any inputs on this will be appreciated.

[GalaticStryder]

For reference this is the complete response: https://gist.github.com/GalaticStryder/e7b3423aa6f8b752bbb84c93726f5332 for JSON parts.