DTP (Test > Production: dc4db3ea) - #48059

Quoting from the documentation ([docs.rubocop.org](https://docs.rubocop.org/rubocop-rails/cops_rails.html#railsblank), [rubydoc.info](https://www.rubydoc.info/gems/rubocop-rails/RuboCop/Cop/Rails/Blank)):

> Checks for code that can be written with simpler conditionals using `Object#blank?` defined by Active Support.

There is certainly an argument to be made that there are situations in which `!foo.present?` and `something unless foo.present?` can be more readable than `foo.blank?` and `something if foo.blank?`, depending on the specific variable names involved, but I think they're rare enough that the consistency we gain by enabling this rule is worth it.

Fix Violations of and Reenable `Rails/Blank`

DTT (Staging > Test) [robo-dtt]

DTT (Staging > Test) [robo-dtt]

…nflicts

DTS (Levelbuilder > Staging) [mike]

Delete discountcode page and components

WebSerial on Chromebooks

* add and update modules

* add images

* css updates after review

* move grades after image in module partial

* drop table migration

* updated schema

…r-test

DTT (Staging > Test) [robo-dtt]