libnotificationmanager: escape less-than sign in notification body
Test:
notify-send "Broken Notification" "<fusionfuture:kde.org>: Hello World"
notify-send "Broken Notification" "<fusionfuture:kde.org: Hello World"
Test:
notify-send "Broken Notification" "<fusionfuture:kde.org>: Hello World"
notify-send "Broken Notification" "<fusionfuture:kde.org: Hello World"