[web/data] Fix userCallbackThenUpdateUI to completely replace old DOM elements
Without the 'swap' parameter, userCallbackThenUpdateUI() would replace
the _children_ of the component with a new version of the componenent,
thus creating nested divs/spans/buttons/etc.
Closes #4881299
cubicweb-web: embedded-javascript-library usr/share/cubicweb/cubes/shared/data/jquery.js