fix method name

Author: SimonBlanke

src/gradient_free_optimizers/optimizers/global_opt/powells_method/direction.py

@@ -14,7 +14,7 @@ def __init__(self, position_1, position_2) -> None:
         self.position_1 = position_1
         self.position_2 = position_2
 
-    def get_position_on_vector(self, t):
+    def get_new_position(self, t):
         """
         Calculate a position on the line (vector) between two positions using parameter t.