shared: Introduce IndexSyncer, containing logic of cli/CommandUpdate

IndexSyncer contains most of the logic of cli/CommandUpdate, so
it can be reused in the GUI where we need it too

shared/indexsyncer.h

@@ -0,0 +1,36 @@
+#ifndef INDEXSYNCER_H
+#define INDEXSYNCER_H
+#include "sqlitedbservice.h"
+
+class IndexSyncer : public QObject
+{
+	Q_OBJECT
+  private:
+	SqliteDbService *dbService = nullptr;
+	bool keepGoing = true;
+	bool removeDeletedFromIndex = true;
+	bool dryRun = false;
+	bool verbose = false;
+	QString pattern;
+
+  public:
+	IndexSyncer(SqliteDbService &dbService);
+
+  public slots:
+	void sync();
+	void setDryRun(bool dryRun);
+	void setVerbose(bool verbose);
+	void setKeepGoing(bool keepGoing);
+	void setRemoveDeletedFromIndex(bool removeDeletedFromIndex);
+	void setPattern(QString pattern);
+
+  signals:
+	void error(QString error);
+	void removed(QString path);
+	void removedDryRun(QString path);
+	void updatedDryRun(QString path);
+	void updated(QString path);
+	void finished(unsigned int totalUpdated, unsigned int totalDeleted, unsigned int totalErrored);
+};
+
+#endif // INDEXSYNCER_H