Combobox: autocomplete does not follow W3C mouse interaction behavior

[ianmcburnie]

Compare makeup autocomplete examples here: https://makeup.github.io/makeup-js/ui/makeup-combobox/index.html

With W3C example: https://www.w3.org/WAI/ARIA/apg/patterns/combobox/examples/combobox-autocomplete-list/

See that the W3C example always filters the list, even when a selection is made with mouse. I don't know when or why makeup deviated from this (bug or oversight) but I think we need to bring the default behavior back in line with the W3C example. Some people have mentioned that the mouse behavior of the makeup example is a better ux, therefore we could add a configuration option to opt into that behaviour.