NEW: Add Ellis' pattern method for pressure advance calibration

Add a new calibration pattern method for pressure advance calibration, which can better test the influence of k value on the corner. The changes of this patch are picked from OrcaSlicer by thewildmage, thanks to thewildmage for the great work!

github issue: https://github.com/bambulab/BambuStudio/issues/2222

Change-Id: Icc8fd4d52b20c1668bfa08716b48549dfada515b
(cherry picked from commit eb72d8b681bef270906406a2d10a36d4efbce900)

src/libslic3r/Model.hpp

@@ -21,6 +21,8 @@
 //BBS: add stl
 #include "Format/STL.hpp"
 
+#include "Calib.hpp"
+
 #include <map>
 #include <memory>
 #include <string>
@@ -1624,6 +1626,8 @@ public:
     // Checks if any of objects is painted using the multi-material painting gizmo.
     bool          is_mm_painted() const;
 
+    std::unique_ptr<CalibPressureAdvancePattern> calib_pa_pattern;
+
 private:
     explicit Model(int) : ObjectBase(-1)
         {