LC: Add begin and end kp and fix the convertion bug.

src/Model/Geometry/Reach.py

@@ -201,6 +201,12 @@ class Reach:
         """
         return [profile.kp for profile in self.profiles]
 
+    def get_kp_min(self):
+        return min([profile.kp for profile in self.profiles])
+
+    def get_kp_max(self):
+        return max([profile.kp for profile in self.profiles])
+
 
     # Guidelines