feat(mobile): implement simple slide effect for tree

src/public/app/widgets/mobile_widgets/sidebar_container.js

@@ -0,0 +1,19 @@
+import FlexContainer from "../containers/flex_container.js";
+
+export default class SidebarContainer extends FlexContainer {
+
+    constructor(screenName, direction) {
+        super(direction);
+
+        this.screenName = screenName;
+    }
+
+    activeScreenChangedEvent({activeScreen}) {
+        if (activeScreen === this.screenName) {
+            this.$widget.addClass('show');
+        } else {
+            this.$widget.removeClass('show');
+        }
+    }
+
+}