Allow Data decimation for line like custom charts

[tdymel]

Feature Proposal

I suggest that every chart type that extends LineController should be applicable to the decimation plugin.

Currently due to this line, this is not possible:

if (meta.type !== 'line') {
        // Only line datasets are supported
        return;
}

Feature Use Case

I extend the LineController in order to use a line chart, but to also extend the graph with a fancy hover animation, were a custom Pin is shown to highlight the "X" position. As this is still a line chart, I would still really like to make use of the decimation plugin.

Possible Implementation

I dont know the code base. Ideally it would be something along the lines that you check the if something is a LineController.
I can also see that you could add another option like isDecimatable, so a user can tell you that its fine anyway?

if (meta instanceOf LineController) {
        return;
}

[ShaneZhengNZ]

Totally agree with this. I am trying to get Decimation working on a scatter chart. From my perspective, the scatter chart should be compatible with the line chart data decimation.

[etimberg]

I opened #10182 to support this. Each controller now exposes a supportsDecimation boolean that if true, enables the decimation plugin.