add Ctrl+8 navigation shortcut for radios page

ui/browsing/browsingpane.go

@@ -164,7 +164,7 @@ func (b *BrowsingPane) EnableNavigationButtons() {
 func (b *BrowsingPane) ActivateNavigationButton(num int) {
 	if num < len(b.navBtnsContainer.Objects) {
 		btn := b.navBtnsContainer.Objects[num].(*widget.Button)
-		if !btn.Disabled() {
+		if !btn.Disabled() && !btn.Hidden {
 			btn.OnTapped()
 		}
 	}

ui/mainwindow.go

@@ -36,9 +36,10 @@ var (
 	ShortcutNavFive  = desktop.CustomShortcut{KeyName: fyne.Key5, Modifier: os.ControlModifier}
 	ShortcutNavSix   = desktop.CustomShortcut{KeyName: fyne.Key6, Modifier: os.ControlModifier}
 	ShortcutNavSeven = desktop.CustomShortcut{KeyName: fyne.Key7, Modifier: os.ControlModifier}
+	ShortcutNavEight = desktop.CustomShortcut{KeyName: fyne.Key8, Modifier: os.ControlModifier}
 
 	NavShortcuts = []desktop.CustomShortcut{ShortcutNavOne, ShortcutNavTwo, ShortcutNavThree,
-		ShortcutNavFour, ShortcutNavFive, ShortcutNavSix, ShortcutNavSeven}
+		ShortcutNavFour, ShortcutNavFive, ShortcutNavSix, ShortcutNavSeven, ShortcutNavEight}
 )
 
 type MainWindow struct {