data: Add back (hidden) shortcuts for vertical navigation

Users who customized their workspace shortcuts before updating to
GNOME 40 are experiencing troubles when trying to use the same
keybinding for the horizontal shortcuts, because of hidden conflicts
with the vertical ones.

We can address this by registering the old shortcuts with Settings
without showing them in the UI, so that they are taken into account
by Settings' conflict resolution.

https://gitlab.gnome.org/GNOME/mutter/-/issues/1740

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1814>

data/50-mutter-navigation.xml

@@ -26,6 +26,14 @@
 	<KeyListEntry name="move-to-workspace-right"
 	              description="Move window one workspace to the right" />
 
+        <KeyListEntry name="move-to-workspace-up"
+                      description="Move window one workspace up"
+                      hidden="true" />
+
+        <KeyListEntry name="move-to-workspace-down"
+                      description="Move window one workspace down"
+                      hidden="true" />
+
 	<KeyListEntry name="move-to-monitor-left"
 	              description="Move window one monitor to the left" />
 
@@ -125,4 +133,12 @@
 	<KeyListEntry name="switch-to-workspace-right"
 	              description="Move to workspace on the right" />
 
+        <KeyListEntry name="switch-to-workspace-up"
+                      description="Move to workspace above"
+                      hidden="true" />
+
+        <KeyListEntry name="switch-to-workspace-down"
+                      description="Move to workspace below"
+                      hidden="true" />
+
 </KeyListEntries>