List the Activity Pager also as an alternative to e.g. the Activity Bar

Summary:
It's useful in both.

BUG:394792

Reviewers: broulik, mart

Reviewed By: broulik

Subscribers: ngraham, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D13175

applets/activitypager/metadata.desktop

@@ -85,7 +85,7 @@ Type=Service
 X-Plasma-API=declarativeappletscript
 X-KDE-ServiceTypes=Plasma/Applet
 X-Plasma-MainScript=ui/main.qml
-X-Plasma-Provides=org.kde.plasma.virtualdesktops
+X-Plasma-Provides=org.kde.plasma.virtualdesktops,org.kde.plasma.activities
 X-KDE-PluginInfo-Author=The Plasma Team
 X-KDE-PluginInfo-Email=plasma-devel@kde.org
 X-KDE-PluginInfo-Name=org.kde.plasma.activitypager