Legend sizing fails on long legend labels

[nickofthyme]

Describe the issue

Creating a chart with a legend that contains one or more labels that are very long, the Settings.legendSize prop is not handled as expected. The size is limited by 30% of the max label width.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/long-legend-sizing-xq2sky?file=/src/App.tsx
2. Change the Settings.legendSize prop and notice with the very long label the size is ignored.

Expected behaviour
Legend size is limited to the provided size

Screenshots

Screen.Recording.2023-10-12.at.11.39.46.AM.mp4

Additional Context

elastic-charts/packages/charts/src/state/selectors/get_legend_size.ts

Lines 69 to 85 in 7e319d5

	if (legendPosition.direction === LayoutDirection.Vertical) {
	const legendItemHeight = bbox.height + VERTICAL_PADDING * 2;
	const legendHeight = legendItemHeight * labels.length + TOP_MARGIN;
	const scrollBarDimension = legendHeight > parentDimensions.height ? SCROLL_BAR_WIDTH : 0;
	const staticWidth = spacingBuffer + actionDimension + scrollBarDimension;
	const width = Number.isFinite(legendConfig.legendSize)
	? Math.min(Math.max(legendConfig.legendSize, legendItemWidth * 0.3 + staticWidth), parentDimensions.width * 0.7)
	: Math.floor(Math.min(legendItemWidth + staticWidth, verticalWidth));
	return {
	width,
	height: legendHeight,
	margin,
	position: legendPosition,
	};
	}

The main issue of the logic is at line 76 in which we clamp the width based on size of the labels. I think we are missing a check on when to use the constraints as an upper or lower bound, need to dig a little deeper.