Support XDG activation

QWaylandLayerShellIntegration has virtual hooks for Xdg Activation.

This is important to hook up in layer shell because activation using
requestActivate in Qt will go through this path. It also means we have
support for us to drop the implementation in KWindowSystem in favour of
calling into Qt.

src/qwaylandxdgactivationv1.cpp

@@ -0,0 +1,44 @@
+/** Copyright (C) 2020 Aleix Pol Gonzalez <aleixpol@kde.org>
+ *   SPDX-License-Identifier: LGPL-3.0-or-later
+ */
+
+#include "qwaylandxdgactivationv1_p.h"
+#include <QtWaylandClient/private/qwaylanddisplay_p.h>
+#include <QtWaylandClient/private/qwaylandinputdevice_p.h>
+
+QWaylandXdgActivationV1::QWaylandXdgActivationV1()
+    : QWaylandClientExtensionTemplate<QWaylandXdgActivationV1>(1)
+{
+    initialize();
+}
+
+QWaylandXdgActivationV1::~QWaylandXdgActivationV1()
+{
+    if (isActive()) {
+        destroy();
+    }
+}
+
+QWaylandXdgActivationTokenV1 *QWaylandXdgActivationV1::requestXdgActivationToken(QtWaylandClient::QWaylandDisplay *display,
+                                                                                 struct ::wl_surface *surface,
+                                                                                 std::optional<uint32_t> serial,
+                                                                                 const QString &app_id)
+{
+    auto wl = get_activation_token();
+    auto provider = new QWaylandXdgActivationTokenV1;
+    provider->init(wl);
+
+    if (surface) {
+        provider->set_surface(surface);
+    }
+    if (!app_id.isEmpty()) {
+        provider->set_app_id(app_id);
+    }
+    if (serial && display->lastInputDevice()) {
+        provider->set_serial(*serial, display->lastInputDevice()->wl_seat());
+    }
+    provider->commit();
+    return provider;
+}
+
+#include "moc_qwaylandxdgactivationv1_p.cpp"