[notifications applet] Fix two qml warnings about assigning [undefined]
Summary:
Fixes
[...]/NotificationDelegate.qml:51:26: Unable to assign [undefined] to int
by using the correct name of the enum value.
[...]/NotificationDelegate.qml:122:33: Unable to assign [undefined] to bool
by proper initialization of notification model data
Test Plan: No more warnings e.g. on notifications for new emails from akonadi.
Reviewers: Plasma, broulik
Reviewed By: Plasma, broulik
Subscribers: broulik, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D11743