Suggest correct column ordering for new tables

Context:

For GitLab we require that columns of new tables are ordered to use the least amount of space. An easy way of doing this is to order them based on the type size in descending order with variable sizes (text, varchar, arrays, json, jsonb, and so on) at the end.

Deliverable:

The database testing tool can add a comment with a column order suggestion for the new table.

https://docs.gitlab.com/ee/development/database/ordering_table_columns.html#ordering-table-columns-in-postgresql