fixed PY-9253 Broken "add field to class" adds the field to the instance instead.

moved tests to the separate testCase

python/testData/quickFixes/AddFieldQuickFixTest/addClassField_after.py

@@ -0,0 +1,10 @@
+__author__ = 'ktisha'
+
+class A(object):
+
+    FIELD = None
+
+    def method(self):
+        var = A.FIELD
+        var = self.test
+