Reorganize files in pglablib

The enitities and containers of the catalog now go into catalog subfolder
Models go into model

pglablib/catalog/PgClassContainer.h

@@ -0,0 +1,24 @@
+#ifndef PGCLASSCONTAINER_H
+#define PGCLASSCONTAINER_H
+
+#include "PgContainer.h"
+#include "PgClass.h"
+
+namespace Pgsql {
+
+	class Result;
+
+}
+
+
+class PgClassContainer: public PgContainer<PgClass> {
+public:
+	using PgContainer<PgClass>::PgContainer;
+
+	virtual std::string getLoadQuery() const override;
+protected:
+	PgClass loadElem(const Pgsql::Row &row) override;
+private:
+};
+
+#endif // PGCLASSCONTAINER_H