[COMPONENTS][Collection] Added PrependActorsCollection event [COMPONENTS][Group] Added getGroupCreateForm, used in PrependActorsCollection event to build create a new Group form view

[COMPONENTS][LeftPanel] Removed onEndShowStyles event since the corresponding CSS needed is now consolidated into the default_theme itself [COMPONENTS][RightPanel] Deleted components/RightPanel/RightPanel.php, since its only method (onEndShowStyles) wasn't needed anymore

components/LeftPanel/LeftPanel.php

@@ -67,17 +67,4 @@ class LeftPanel extends Component
             return Event::stop;
         }
     }
-
-    /**
-     * Output our dedicated stylesheet
-     *
-     * @param array $styles stylesheets path
-     *
-     * @return bool hook value; true means continue processing, false means stop
-     */
-    public function onEndShowStyles(array &$styles, string $route): bool
-    {
-        $styles[] = 'components/LeftPanel/assets/css/view.css';
-        return Event::next;
-    }
 }