Gridmap editor now lists plane instead of floor when not horizontal.

Instead of gridmap editor calling grid as floor irrespective of the
orientation, it now calls the grid plane if it's vertical and floor
if horizontal.

Resolves: #14611

modules/gridmap/grid_map_editor_plugin.h

@@ -82,6 +82,7 @@ class GridMapEditor : public VBoxContainer {
 	ConfirmationDialog *settings_dialog;
 	VBoxContainer *settings_vbc;
 	SpinBox *settings_pick_distance;
+	Label *spin_box_label;
 
 	struct SetItem {