TimePoint support for time series

### Feature Proposal

Time series are so common, it seems like a TimePoint or something similar should be a standard point type with a structure like { date: Date | string, y: number }.

As I understand it, you currently have to define a custom data point type and discover this syntax for the chart data: ChartData<'line', TimePoint[]>.

The chart options don't seem to be aware of the custom data point type. The tooltip label callback doesn't know about the custom data point type, so I had to use a ts-ignore in my code to ignore the issue.

I'm not a full TS or chart.js expert, so I may have missed something, but that's kind of the point. Time series is one of the most common chart types and should be easy to use with TypeScript.

### Possible Implementation

Similar to BubblePoint, add a TimePoint type that supports Date objects and parsable date strings.