refactor: align properties (SAP#9319)

Author: nnaydenow

packages/fiori/src/ProductSwitchItem.hbs

@@ -8,7 +8,7 @@
 		@keyup="{{_onkeyup}}"
 		tabindex={{forcedTabIndex}}
 		href="{{targetSrc}}"
-		target="{{target}}">
+		target="{{_effectiveTarget}}">
 		{{> item}}
 	</a>
 {{else}}

packages/fiori/src/ProductSwitchItem.ts

@@ -92,11 +92,13 @@ class ProductSwitchItem extends UI5Element implements IProductSwitchItem {
 	 * - `_blank`
 	 * - `_parent`
 	 * - `_search`
-	 * @default "_self"
+	 *
+	 * **Note:** By default target will be open in the same frame as it was clicked.
+	 * @default undefined
 	 * @public
 	 */
 	@property()
-	target = "_self";
+	target?: string;
 
 	/**
 	 * Defines the component target URI. Supports standard hyperlink behavior.
@@ -154,6 +156,10 @@ class ProductSwitchItem extends UI5Element implements IProductSwitchItem {
 		this.active = true;
 	}
 
+	get _effectiveTarget() {
+		return this.target || "_self";
+	}
+
 	_onkeydown(e: KeyboardEvent) {
 		if (isSpace(e) || isEnter(e)) {
 			this.active = true;

packages/main/src/ComboBoxItemGroup.ts

@@ -19,11 +19,11 @@ import type { IComboBoxItem } from "./ComboBox.js";
 class ComboBoxItemGroup extends UI5Element implements IComboBoxItem {
 		/**
 		 * Defines the text of the component.
-		 * @default ""
+		 * @default undefined
 		 * @public
 		 */
 		@property()
-		headerText = "";
+		headerText?: string;
 
 		/**
 		 * Indicates whether the item is focused

packages/main/src/MultiComboBoxItemGroup.ts

@@ -20,11 +20,11 @@ import type MultiComboBoxItem from "./MultiComboBoxItem.js";
 class MultiComboBoxItemGroup extends UI5Element implements IMultiComboBoxItem {
 	/**
 	 * Defines the text of the component.
-	 * @default ""
+	 * @default undefined
 	 * @public
 	 */
 	@property()
-	headerText = "";
+	headerText?: string;
 
 	/**
 	 * Defines the items of the <code>ui5-mcb-item-group</code>.