Reduce noise in signatures of compiled params (#1564)

* Remove "typing." prefix from compiled signature param

* Don't print default "None" for Optional params

* Don't remove 'typing.' prefix if symbol doesn't come from typing module

* Revert "Don't print default "None" for Optional params"

This reverts commit 8db334d9bb.

* Make sure "typing." doesn't appear in the middle

* Make sure only "typing." prefix is removed and not it's entries in the middle

* Use inspect.formatannotation() to create an annotation string

* Update AUTHORS.txt

* Add test for compiled param annotation string

* Replace Optional in test with other typing facilities

in order for test to be forward-compatible with 3.9

* Add an empty string fallback for Python 2

* Move _annotation_to_str back to original position

jedi/inference/compiled/access.py

@@ -485,9 +485,9 @@ class DirectObjectAccess(object):
         return inspect.isclass(self._obj) and self._obj != type
 
     def _annotation_to_str(self, annotation):
-        if isinstance(annotation, type):
-            return str(annotation.__name__)
-        return str(annotation)
+        if py_version < 30:
+            return ''
+        return inspect.formatannotation(annotation)
 
     def get_signature_params(self):
         return [