Add back X-KDE-ParentApp entries in metadata.desktop

Issue with notifications applet not appearing is fixed in
plasma-framework now

This reverts commit c21c63fe71.

applets/digital-clock/package/metadata.desktop

@@ -133,7 +133,7 @@ Comment[zh_TW]=以數位格式顯示時間
 
 Icon=preferences-system-time
 Type=Service
-X-KDE-ParentApp=
+X-KDE-ParentApp=org.kde.plasmashell
 X-KDE-PluginInfo-Author=Martin Klapetek
 X-KDE-PluginInfo-Email=mklapetek@kde.org
 X-KDE-PluginInfo-License=GPL-2.0+

applets/notifications/package/metadata.desktop

@@ -148,7 +148,7 @@ Comment[zh_TW]=顯示通知與工作
 
 Type=Service
 Icon=preferences-desktop-notification-bell
-X-KDE-ParentApp=
+X-KDE-ParentApp=org.kde.plasmashell
 X-KDE-PluginInfo-Author=Kai Uwe Broulik
 X-KDE-PluginInfo-Category=Tasks
 X-KDE-PluginInfo-Email=kde@privat.broulik.de

wallpapers/color/metadata.desktop

@@ -87,7 +87,7 @@ Comment[zh_TW]=普通顏色桌布
 Type=Service
 
 X-KDE-ServiceTypes=Plasma/Wallpaper
-X-KDE-ParentApp=
+X-KDE-ParentApp=org.kde.plasmashell
 X-KDE-PluginInfo-Author=Marco Martin
 X-KDE-PluginInfo-Category=
 X-KDE-PluginInfo-Email=mart@kde.org

wallpapers/image/imagepackage/metadata.desktop

@@ -117,7 +117,7 @@ Comment[zh_TW]=以桌布視角觀看圖片
 Type=Service
 
 X-KDE-ServiceTypes=Plasma/Wallpaper
-X-KDE-ParentApp=
+X-KDE-ParentApp=org.kde.plasmashell
 X-KDE-PluginInfo-Author=Marco Martin
 X-KDE-PluginInfo-Category=
 X-KDE-PluginInfo-Email=mart@kde.org

wallpapers/image/slideshowpackage/metadata.desktop

@@ -116,7 +116,7 @@ Comment[zh_TW]=投影播放桌布
 Type=Service
 
 X-KDE-ServiceTypes=Plasma/Wallpaper
-X-KDE-ParentApp=
+X-KDE-ParentApp=org.kde.plasmashell
 X-KDE-PluginInfo-Author=Marco Martin
 X-KDE-PluginInfo-Category=
 X-KDE-PluginInfo-Email=mart@kde.org