Extract some logic from SuggestAppsDialog to a separate class

ui/file_manager/file_manager/foreground/css/file_manager.css

Index: ui/file_manager/file_manager/foreground/css/file_manager.css
diff --git a/ui/file_manager/file_manager/foreground/css/file_manager.css b/ui/file_manager/file_manager/foreground/css/file_manager.css
index cd14a927ef25a0558500766a211ad4fdca8624c1..607404247bb4f4164583d75138e74175879d1196 100644
--- a/ui/file_manager/file_manager/foreground/css/file_manager.css
+++ b/ui/file_manager/file_manager/foreground/css/file_manager.css
@@ -1837,11 +1837,11 @@ list.autocomplete-suggestions > [lead] {
   position: relative;
 }
 
-#suggest-app-dialog.show-spinner #webview-container webview {
+#suggest-app-dialog #webview-container.show-spinner webview {
   pointer-events: none;
 }
 
-#suggest-app-dialog:not(.show-spinner) .spinner-layer {
+#suggest-app-dialog #webview-container:not(.show-spinner) .spinner-layer {
   display: none;
 }