PY-10829 Extracted function is inserted *after* the function where it is used

I updated test data accordingly and removed now obsolete tests about
skipping preceding comments.

python/testData/refactoring/extractmethod/ClassMethod.after.py

@@ -1,8 +1,8 @@
 class C:
-    @classmethod
-    def baz(cls):
-        print('foo', cls)
-
     @classmethod
     def foo(cls):
         cls.baz()
+
+    @classmethod
+    def baz(cls):
+        print('foo', cls)