Investigate writeTextToCanvas and measureText function

[ebogo1]

In #9765 we settled on a manual pixel-counting approach instead of using the stock browser function CanvasRenderingContext2D.measureText(). This is because browser results were inconsistent, and at the time of the PR, some of the TextMetrics properties were unsupported by Firefox for Android.

If CanvasRenderingContext2D.measureText(), it would be cleaner to use it instead of drawing the text to a canvas and counting each pixel. Instead we could replace ascent, descent, and minx by the TextMetrics properties actualBoundingBoxAscent, actualBoundingBoxDescent, and actualBoundingBoxLeft.

Until then, maybe it's worth taking another look at why writeTextToCanvas is needed..

[javagl]

Related to #10649 (comment) : It might be easy to replace this function with the built-in functions now.

[ggetz]

Additional issues reported in #11705.