Move timestamp columns to the top

[ceritium]

Summary

Closes #42582

Almost every model gets new columns after creation, leaving the timestamps at
an awkward position between the initial columns and everything else.

For the command bin/rails g model Book title it will generate:

class CreateBooks < ActiveRecord::Migration[7.0]
  def change
    create_table :books do |t|
      t.timestamps

      t.string :title
    end
  end
end

[rafaelfranca]

Thank you for the pull request but I don't think we have enough reason to change this. Like you said, it is just a cosmetic change that doesn't increase usability of the framework neither make anything easier to perform with it, so I prefer to not accept.