Allow sum/diff... y values depending on time unit

### Feature Proposal

Hello,
Instead of writing a custom function to manipulate the data for y values if the unit time is the same,
it would be great to have a parameter in the options to sum/diff... them.
Thank you
```js
const ctx = document.getElementById("tests-chart")
const testsChart = new Chart(ctx, {
type: "bar",
data: {
datasets: [
{
label: 'Dataset 1',
data: [
{ x: "24/03/2022", y: 20 },
{ x: "25/03/2022", y: 5 },
{ x: "24/06/2022", y: 10 },
{ x: "25/06/2022", y: 5 },
],
backgroundColor: 'rgb(255, 99, 132)',
},
],
},
options: {
scales: {
x: {
type: "time",
time: {
parser: "dd/MM/yyyy",
unit: "month",
// Luxon format string
tooltipFormat: "MM",
round: 'month'
},
},
},
},
})
```

Example : https://stackoverflow.com/a/71333407/6837428

### Possible Implementation

_No response_