KateSearchBar: prefer action texts over Yes / No buttons in dialogs

As recommended by KDE HIG -> https://develop.kde.org/hig/components/assistance/message/

Using the same button text as also seen with KFind::shouldRestart(): https://invent.kde.org/frameworks/ktextwidgets/-/blob/master/src/findreplace/kfind.cpp#L745

Though could not yet find a way to trigger that dialog to test the change, is this perhaps even dead code?