Reorganize files in pglablib

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

pglablib/catalog/PgAttributeContainer.h

@@ -0,0 +1,20 @@
+#ifndef PGATTRIBUTECONTAINER_H
+#define PGATTRIBUTECONTAINER_H
+
+#include "PgContainer.h"
+#include "PgAttribute.h"
+#include "Pgsql_declare.h"
+#include <vector>
+
+class PgAttributeContainer : public PgContainer<PgAttribute, PgAttribute::Key> {
+public:
+	using PgContainer<PgAttribute, PgAttribute::Key>::PgContainer;
+
+	virtual std::string getLoadQuery() const override;
+
+	std::vector<PgAttribute> getColumnsForRelation(Oid oid) const;
+protected:
+	PgAttribute loadElem(const Pgsql::Row &row) override;
+};
+
+#endif // PGATTRIBUTECONTAINER_H