Fix missing annotation for Active Record ignored columns

[bensheldon]

Currently, columns that are ignored within Active Record models are not displayed as part of the schema annotation. e.g.

class Post < ApplicationRecord
  self.ignored_columns += ["foobar"]
end

... will result in the foobar column not appearing in the annotation comment.

This behavior has caused problems when a developer has gone to remove an entry from the AR ignored_columns because they thought it was no longer needed because they were referencing the annotation comment where it did not appear.

Ideally, I would like the column to exist in the annotation comment, because the column is present in the database schema.

(I believe this feature is different than the annotaterb ignored-columns feature)