Close the tooltip after certain delay

### Feature Proposal

I would like a way to force the tooltip to close after a certain delay if the mouse/pointer has not moved.
This would be super usefull, especially on mobile devices where the tooltip sometimes stays open indefinitely.
My suggestion would be to add an option to the tooltip, specifying a way to close the tooltip after a certain delay.

### Possible Implementation

I believe debouncing should be used here to reset the timer to the `closeAfterDelay` value when clicking/hovering a new datapoint.

```
options: {
plugins: {
tooltip: {
closeAfterDelay: 3000, // Force the tooltip to close after 3 seconds
}
}
}
}
```