Consistently use "Exit Full Screen" as the action name

It was "Leave Full Screen" in the menus, which is a less common wording
for this.

src/qml/ApplicationMenu.qml

@@ -22,7 +22,7 @@ Menu {
     property var configureAction: ElisaApplication.action("options_configure")
 
     Action {
-        text: mainWindow.visibility == Window.FullScreen ? i18nc("@action:inmenu", "Leave Full Screen") : i18nc("@action:inmenu", "Enter Full Screen")
+        text: mainWindow.visibility == Window.FullScreen ? i18nc("@action:inmenu", "Exit Full Screen") : i18nc("@action:inmenu", "Enter Full Screen")
         icon.name: mainWindow.visibility == Window.FullScreen ? "view-restore" : "view-fullscreen"
         onTriggered: mainWindow.visibility == Window.FullScreen ? mainWindow.showNormal() : mainWindow.showFullScreen()
     }

src/qml/NativeGlobalMenu.qml

@@ -59,7 +59,7 @@ MenuBar {
         }
 
         MenuItem {
-            text: mainWindow.visibility == Window.FullScreen ? i18nc("@action:inmenu", "Leave Full Screen") : i18nc("@action:inmenu", "Enter Full Screen")
+            text: mainWindow.visibility == Window.FullScreen ? i18nc("@action:inmenu", "Exit Full Screen") : i18nc("@action:inmenu", "Enter Full Screen")
             iconName: mainWindow.visibility == Window.FullScreen ? "view-restore" : "view-fullscreen"
             onTriggered: mainWindow.visibility == Window.FullScreen ? mainWindow.showNormal() : mainWindow.showFullScreen()
         }