notification: use viewargs for notif_entity_updated instead of transaction_data
Now that notifications use separate sessions, they can't rely on the
original transaction_data being around, so pass the data through view
arguments instead, so the notification view knows what changed on
updated entities.
Closes #2936180
Experiment with the search bar. Try queries like "card sometextualcontent" or
"card wikiid index" or "345".