New features

Issue #3076134 by alexharries, fago, tamarpe: Support entering documents by URL.

• Refactor controllers and use the same Twig template for every listing page, except Roles (App listing, App listing by developer, Team listing, Team App listing, Team App listing by Team, Member listing).
• Refactor form alters to work with every Apigee Edge entity
• Use apigee_entity.html.twig as a base for app and team templates

* SCSS and CSS improvements [https://www.drupal.org/project/bootstrap4/issues/3131466]
* Drupal 9 compatibility [https://www.drupal.org/project/bootstrap4/issues/3131467]
* Error copying new subtheme via interface and enabling it [https://www.drupal.org/project/bootstrap4/issues/3123296]

#3131477: Remove use of deprecated views plugin

#3131475: d9 compatibility
#3006528: Capitalize module name per Drupal standards

First Drupal 9 compatible version of Guardr Core