[Feature Request] Async charts for cases when data/series calculation is heavy (separate chart instantiation and calculation)

[alies-dev]

Is your feature request related to a problem? Please describe.
If a chart requires heavy to calculate data, the whole page will be empty unless data calculate. This is how response of available cards looks like (for dashboard, UEL example /nova-api/dashboards/users):

Describe the solution you'd like
What Nova does with their default charts is to serialise meta data about the Metric and then associated vue component produces a request to fetch data for the Metric.

I tried to use LineChart is the same fashion:

final class MembershipLifetimeLIneChart extends Metric

    /** This method is called by {@see \Laravel\Nova\Metrics\Metric::resolve} */
    public function calculate(Request $request): \JsonSerializable
    {
        return LineChart::make()
            ->title($this->name())
            ->series([
                [...

but it also requires to update vue components to support such behaviour: existing components can't parse metric metadata and then produce an API request.

Nova bug makes it even more important

For every request to a Metric, added to a dashboard, Nova calls public static function allAvailableDashboardCards(NovaRequest $request) that initialises all cards and metrics. In case of this package that means if you have 20 charts on a dashboard, Nova will initialise them 20*20 times. Of course, that means a lot of DB queries if you fetch info for charts from DB. Implementation of this feature will solve this problem: chart instantiation and calculation will be different processes

[bkuhl]

I'm glad I saw this, thank you, I'll have to hold off on this package for now. I was wondering if this was the case given how the docs didn't suggest to build an object for each metric, but put it directly in the dashboard object itself...