Reload virtual desktop name on change

Summary:
PlasmaVirtualDesktop at a protocol level is double buffered.

There's a done() command emitted after property changes. After this the
name might have changed.

Test Plan:
Changed a desktop name (with relevant kwin patch)
Name changed in the pager tooltip

Reviewers: #plasma, hein

Reviewed By: #plasma, hein

Subscribers: zzag, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D18512

libtaskmanager/virtualdesktopinfo.cpp

@@ -364,6 +364,12 @@ void VirtualDesktopInfo::WaylandPrivate::addDesktop(const QString &id, quint32 p
         }
     );
 
+    QObject::connect(desktop, &KWayland::Client::PlasmaVirtualDesktop::done, q,
+        [this]() {
+            emit desktopNamesChanged();
+        }
+    );
+
     if (desktop->isActive()) {
         currentVirtualDesktop = id;
         emit currentDesktopChanged();