Adding document's Grand Total

Document details endpoint and Webhooks now return information about document's Grand Total.

API example:

{
    ...
    "id": "WHT7fGF2QeWSTZEsg6un75",
    "grand_total": {
        "amount": "29.99",
        "currency": "USD"
    },
    ...
}

Webhook example:

{
    "data": {
        ...
        "id": "WHT7fGF2QeWSTZEsg6un75",
        "grand_total": {
        "amount": "29.99",
        "currency": "USD"
        },
        ...
    },
    "event": "document_state_changed"
}