Dev/drupal standards

This merge request is meant to bring our backend code into compliance with Drupal coding standards. Part of our application for security coverage. See https://www.drupal.org/project/projectapplications/issues/3195949#comment-13998133

The majority of files changed were simply to reduce indentation from 4 spaces to 2 spaces. However, I also made some significant changes to the SupportChatController to enable dependency injection instead of using the \Drupal class.

Other changes included spacing and naming conventions (function names and variables using snake_case, method names using lowerCamelCase).