ENH: Add gaps in the outer wall of the wipe_tower

and modify the path of travel to the wipe_tower after flushing

jira:none

Change-Id: Id4b0571fd12372c59cf522c13e256c7cc4ac3565
(cherry picked from commit 17771d0fbf753dd22411ce490586958bd643264e)

src/libslic3r/Print.hpp

@@ -1038,7 +1038,7 @@ public:
     void set_calib_params(const Calib_Params& params);
     const Calib_Params& calib_params() const { return m_calib_params; }
     Vec2d translate_to_print_space(const Vec2d &point) const;
-
+    float               get_wipe_tower_depth() const { return m_wipe_tower_data.depth; }
 
     // scaled point
     Vec2d translate_to_print_space(const Point &point) const;