Global styles: improve Navigator usage in typography panel (WordPress…

…#65942)

* Global styles: remove trailing slack from font sizes screen path

* Remove unncessary goTo

* Use goBack instead of goTo, add extra slug check to avoid double goBack call

---

Co-authored-by: ciampo <mciampini@git.wordpress.org>
Co-authored-by: tyxla <tyxla@git.wordpress.org>

packages/edit-site/src/components/global-styles/font-sizes/font-size.js

@@ -36,7 +36,7 @@ function FontSize() {
 
 	const {
 		params: { origin, slug },
-		goTo,
+		goBack,
 	} = useNavigator();
 
 	const [ fontSizes, setFontSizes ] = useGlobalSetting(
@@ -53,10 +53,10 @@ function FontSize() {
 
 	// Navigate to the font sizes list if the font size is not available.
 	useEffect( () => {
-		if ( ! fontSize ) {
-			goTo( '/typography/font-sizes/', { isBack: true } );
+		if ( !! slug && ! fontSize ) {
+			goBack();
 		}
-	}, [ fontSize, goTo ] );
+	}, [ slug, fontSize, goBack ] );
 
 	if ( ! origin || ! slug || ! fontSize ) {
 		return null;
@@ -158,7 +158,6 @@ function FontSize() {
 							__( 'Manage the font size %s.' ),
 							fontSize.name
 						) }
-						onBack={ () => goTo( '/typography/font-sizes/' ) }
 					/>
 					{ origin === 'custom' && (
 						<FlexItem>

packages/edit-site/src/components/global-styles/font-sizes/font-sizes-count.js

@@ -24,7 +24,7 @@ function FontSizes() {
 			</HStack>
 			<ItemGroup isBordered isSeparated>
 				<NavigationButtonAsItem
-					path="/typography/font-sizes/"
+					path="/typography/font-sizes"
 					aria-label={ __( 'Edit font size presets' ) }
 				>
 					<HStack direction="row">

packages/edit-site/src/components/global-styles/ui.js

@@ -302,7 +302,7 @@ function GlobalStylesUI() {
 				<ScreenTypography />
 			</GlobalStylesNavigationScreen>
 
-			<GlobalStylesNavigationScreen path="/typography/font-sizes/">
+			<GlobalStylesNavigationScreen path="/typography/font-sizes">
 				<FontSizes />
 			</GlobalStylesNavigationScreen>