Postgres DDL - For create table, improve column ordering for tighter storage

[rbygrave]

For background refer to:
https://www.2ndquadrant.com/en/blog/on-rocks-and-sand/
https://docs.gitlab.com/ee/development/ordering_table_columns.html
https://stackoverflow.com/questions/2966524/calculating-and-saving-space-in-postgresql/7431468#7431468

What this will do is push decimal, varchar, clob and other variable length columns to end of a create table statement.