when multiple styles are added to an element, traverse all children and keep the styles to just one element
change for partially styled elements also, since this case is treated differently
identify partially styled elements even if they are not first level children; use these elements when converting them to svg instead of the root element and add needed styles at the end
treat 'a' and 'li' cases differently since for them a container is returned instead of the given alt
move functionality to method since it is used in 2 places;
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