[css-highlight-api] CSS.highlights: map vs set?

[frivoal]

Should we throw some kind of exception if the same highlight range group is registered twice (or more) under different names? If not, isn’t it an isssue that the several custom highlights that share this highlight range group will not only share the same ranges, but also the same priority and style attribute? This could be solved by making the name an attribute of the highlight range group as well, and then turning CSS.highlights into a setlike of HighlightRangeGroup instead of a maplike of String=>HighlightRangeGroup.

If we did that, we could also probably rename HighlightRangeGroup into Highlight.

[frivoal]

Closed based on a discussion with @sanketj