Fix for chartjs 3

[zachary822]

Update the dist file and use the newer Chart.register instead of Chart.plugin.register.

[Djones4822]

importing this dist using

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.5.0/chart.min.js"> </script>
<script src='js/chartjs-plugin-boxselect.js'></script>

yields an error when I release the box:

chartjs-plugin-boxselect.js:57 Uncaught TypeError: Cannot read properties of undefined (reading 'valueOrDefault')
    at doSelect (chartjs-plugin-boxselect.js:57)
    at Object.afterEvent (chartjs-plugin-boxselect.js:208)
    at Q (chart.min.js:13)
    at Fn._notify (chart.min.js:13)
    at Fn.notify (chart.min.js:13)
    at oo.notifyPlugins (chart.min.js:13)
    at oo._eventHandler (chart.min.js:13)
    at n (chart.min.js:13)
    at oo.e (chart.min.js:13)
    at chart.min.js:7

It appears to be a bug in the factory parameter setting, line 4
global.boxselectplugin = factory(global.Chart, global.helpers));

where you need to have

global.boxselectplugin = factory(global.Chart, global.Chart.helpers));

With that change I am able to import and use successfully. I am not familiar enough with rollup or plugin development to assist further, but I hope this is helpful.

[Djones4822]

I'm also not entirely sure why, but before I could get this working in production nicely with other plugins, I also had to add:

	if (!chart.boxselect) {
		return false;
	}

to the beginning of both afterDraw and beforeTooltipDraw methods