Validator enhancements

Tracker: https://internal-tracker.builder.ai/#/projects/3651?storyId=1951494

This MR contains enhancements to the code validator tool, by employing checks to the code marked with Protected Area (for marked code that should not be changed), in addition to the existing marker using Customizable Area(which indicates code that can be customised). The check for Protected Area can be enabled with a command line option. The tool defaults to using Customizable Area otherwise. Also, unused files have been removed from the repository.