fix: remove slot only for child menu items

Author: mlopezFC

src/main/java/com/flowingcode/addons/applayout/SlottedMenuItem.java

@@ -31,7 +31,9 @@ protected void onAttach(AttachEvent attachEvent) {
     if (getParent().orElse(null) instanceof SlottedMenuItem) {
       getElement().setAttribute("slot", "menu-item");
     } else {
-      getElement().removeAttribute("slot");
+      if ("menu-item".equals(getElement().getAttribute("slot"))) {
+        getElement().removeAttribute("slot");
+      }
     }
     super.onAttach(attachEvent);
   }

src/main/java/com/flowingcode/addons/applayout/ToolbarIconButton.java

@@ -19,6 +19,7 @@
  */
 package com.flowingcode.addons.applayout;
 
+import com.vaadin.flow.component.Component;
 import com.vaadin.flow.component.HasEnabled;
 import com.vaadin.flow.component.Tag;
 import com.vaadin.flow.component.dependency.JsModule;
@@ -31,7 +32,7 @@
 @NpmPackage(value = "@polymer/paper-icon-button", version = "3.0.2")
 @JsModule("@polymer/paper-icon-button/paper-icon-button.js")
 @Tag("paper-icon-button")
-public class ToolbarIconButton extends SlottedMenuItem
+public class ToolbarIconButton extends Component
     implements HasEnabled,
         HasMenuItemCommands<ToolbarIconButton>,
         HasMenuItemIcon<ToolbarIconButton> {