This is a ⚠️ work-in-progress PR to start resolving various theming issues, including primarily #16 and also provides a css-based solution to resolve #19 by adding a class for each bibliographical information.

Here is a copy of the task list from #16 to show progress...

• Separate business logic from display logic in template_preprocess_ebsco_result templates and move as much as possible to ebsco-result.html.twig that can be overridden by a theme.
• Convert auto_link to a Twig filter.
• Separate business logic from display logic in template_preprocess_ebsco_results and move as much as possible to ebsco-results.html.twig that can be overridden by a theme.
• Ensure preprocess code changes follow Drupal 8 PHP syntax coding standards.
• Ensure all Twig templates follow Drupal 8 Twig syntax coding standards.