Implement getColumns for MySQL and Postrgres DB connections

catalogue/CatalogueSchema.cpp

catalogue/CatalogueSchema.hpp

catalogue/VerifySchemaCmd.cpp

common/utils/UtilsTest.cpp

common/utils/utils.cpp

common/utils/utils.hpp

rdbms/Conn.cpp

rdbms/Conn.hpp

rdbms/wrapper/ConnWrapper.hpp

rdbms/wrapper/MysqlConn.cpp

rdbms/wrapper/MysqlConn.hpp

rdbms/wrapper/OcciConn.cpp

rdbms/wrapper/OcciConn.hpp

rdbms/wrapper/PostgresConn.cpp

rdbms/wrapper/PostgresConn.hpp

rdbms/wrapper/SqliteConn.cpp

rdbms/wrapper/SqliteConn.hpp