PLF-5311: Improve labels of Group Navigation and Space Navigation

Fix description:
* In Group Navigation title, keep only the group name.
* In Space Navigation, concatenate the labels for translation purpose.
PLF-5653 i18n in Bookmark gadget
PLF-5631 WARN Cannot find resource bundle for key UIUserPlatformToolBarPortlet.label.find, UIUserNavigationPortlet.label.dashboard

Fix description
* Remove the redundant variable of UIUserPlatformToolBarPortlet.label.find
* Update the condition to not create UIUserNavigationPortlet.label.dashboard.