IE11: insertRule upper limit check (32678)

[vaadin-bot]

Originally by dvekeman

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We have an excel file which we render using Vaadin Spreadsheet. It works fine in most browsers (Safari, Chrome on Win/Mac, Firefox on Win/Mac), except for Internet Explorer (IE 11 on W10).

We have little control over the Spreadsheet and we basically just render it, let the user change some values and that's it.

On IE11 the upper limit for the index of CSStylesheet.insertRule apparently is 32678 so this line

        return stylesheet.sheet.insertRule(css, stylesheet.sheet.cssRules.length);

fails is length exceeds 32768.

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Imported from https://dev.vaadin.com/ issue #19217