[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
Experiment with the search bar. Try queries like "card sometextualcontent" or
"card wikiid index" or "345".