Pass widget again to KNotification on bell
67508680 refactored TerminalBell out from TerminalDisplay, and in the process stopped passing the TerminalDisplay widget to KNotification, which resulted in issues when notifications where configured to mark the task bar entry or run a command with %w/%t substitutions (for window id and window title).
Many thanks to Nicole Kleinhoff and Jan Palus who identified the commit that introduced the regression.