E2256: Refactor late_policies_controller.rb

[kalgeekotak99]

Issues Worked Upon:

• Rename all usages of @penalty_policy to @late_policy within the controller as well as the views
• Refactor the method “duplicate_name_check” such that it doesn’t violate the Single Responsibility Principle.
• Use a better name than “duplicate_name_check”
• Make the validate_input method as “stateless” as possible.
• Update the code so that initially you assume that the penalty is NOT VALID, and then you need to verify that it is valid during validation.
• Fix the Error Message output. It currently prints only one error message even if more than one validation is failing.

[expertiza-travisci-bot]

Hey @kalgeekotak99,
Your changes look good to me! 🎉