PY-12425 Fixed: Completion breaks when implementing a callable object with the __call__ method

Fix callType calculating for class instance: resolve __call__ member and process all possible return types

python/testData/completion/instanceFromInheritedCallAttr.py

@@ -0,0 +1,14 @@
+class Foo(object):
+    bar = True
+
+class FooMakerAnc(object):
+    def __call__(self):
+        return Foo()
+
+class FooMaker(FooMakerAnc):
+    pass
+
+fm = FooMaker()
+f3 = fm()
+
+f3.b<caret>