core: copy Animations from SettingsObjectWrapper to qPref as its own class

Update set/get functions to follow common name scheme:
- get function have same name as in struct preferences
- set function have set_<name in struct preferences>
- signal function have <name in struct preferences>_changed

one class one .h/.cpp is the C++ idiom. Having load/sync of each
variable in 1 functions (in contrast to the distributed way SettingsObjectWrapper
handles it) secures the same storage name is used. Having the set/get/load/sync
functions grouped together makes it easier to get an overview.

REMARK: this commit only defines the class, it is not active in production
Signed-off-by: Jan Iversen <jani@apache.org>

core/settings/qPrefAnimations.h

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef QPREFANIMATIONS_H
+#define QPREFANIMATIONS_H
+
+#include <QObject>
+#include <QSettings>
+
+class qPrefAnimations : public QObject {
+	Q_OBJECT
+	Q_PROPERTY(int animation_speed READ animation_speed WRITE set_animation_speed NOTIFY animation_speed_changed);
+
+public:
+	qPrefAnimations(QObject *parent = NULL);
+	static qPrefAnimations *instance();
+
+	// Load/Sync local settings (disk) and struct preference
+	void loadSync(bool doSync);
+	void load() { loadSync(false); }
+	void sync() { loadSync(true); }
+
+public:
+	int animation_speed() const;
+
+public slots:
+	void set_animation_speed(int value);
+
+signals:
+	void animation_speed_changed(int value);
+
+private:
+	const QString group = QStringLiteral("Animations");
+	QSettings setting;
+
+	// functions to load/sync variable with disk
+	void disk_animation_speed(bool doSync);
+};
+
+#endif