Ember - donation system, bans, loading screen & landing/index page

• Group sync improvements
• Added a field for in-game group names to group settings (to allow for different display names)
• Existing CAMI (ULX etc.) groups are now synced into Ember groups
• Sync for revoked groups has been reinstated
• Other minor improvements

Files modified:

• lua/ember/lua/ember/store.lua
• web/app/Controllers/MigrationController.php
• web/app/Controllers/ServerApiController.php
• web/app/Events/GroupSaving.php
• web/app/Models/Group.php
• web/app/Models/User.php
• web/package-lock.json
• web/package.json
• web/public/css/app.css
• web/public/js/adminvue.js
• web/public/js/app.js
• web/public/mix-manifest.json
• web/resources/js/app.js
• web/resources/sass/app.scss
• web/resources/views/admin/features.twig
• web/resources/views/admin/groups.twig
• web/resources/views/admin/loadingscreens.twig
• web/resources/views/admin/packages.twig
• web/resources/views/dependencycheck.twig
• web/resources/views/templates/app.twig