add trace option to make some data not selectable in order to speed up slow box select

Hi,

When there are a lot of data traces displayed in the plot (>10,000), box select is slow and laggy when you click and drag to select data traces. I notice it is even slower in version plotly.js@2.27.1 than it is in plotly.js@2.5.1. A hypothetical solution for me would be if you added a feature to exclude some traces from being selectable, as in the example below.

Example of proposed feature:

import React from 'react';
import Plot from 'react-plotly.js';

class MyPlot extends React.Component {
  render() {
    return (
      <Plot
        data={[
          {
            x: [1, 2, 3, 4],
            y: [10, 15, 13, 17],
            type: 'scattergl',
            mode: 'lines+markers',
            name: 'Selectable Trace'
          },
          {
            x: [1, 2, 3, 4],
            y: [16, 5, 11, 9],
            type: 'scattergl',
            mode: 'lines+markers',
            name: 'Non-selectable Trace',
            selectable: false   //  <------ THIS IS THE NEW FEATURE THAT IS BEING REQUESTED
          }
        ]}
        layout={{ 
          title: 'Selectable vs Non-selectable Traces'
        }}
      />
    );
  }
}

I have a temporary fix to speed up selection. When I tested this naive change, box select's click and drag is no longer laggy:

// Change in file: plotly.js/src/traces/scattergl/select.js
 module.exports = function select(searchInfo, selectionTester) {
  return [];  // Changed to always return no selected traces, because my own onSelected handler can do all the work using only the selected x, y range coordinates.
 }

If you can tell me how to monkey patch this in, that would be very helpful!

Thanks!

Start with src/traces/scattergl/select.js and review how box selection currently processes traces, using the reported scattergl example as the behavior reference. Determine how a trace-level selectable option should affect selection while preserving selection for other traces. Done means non-selectable traces are excluded and box select is responsive with large datasets.