Ensure *args, **kwargs lookthrough works at module scope too

This means that passthrough signatures will be found for top level
functions, which is useful both where they're wrappered by
`functools.wraps` or not.

Fixes https://github.com/davidhalter/jedi/issues/1791.

test/test_inference/test_signature.py

@@ -292,6 +292,26 @@ def test_pow_signature(Script, environment):
                 return wrapper
 
             x(f)('''), 'f()'],
+        [dedent('''
+            # identifier:C
+            import functools
+            def f(x: int, y: float):
+                pass
+
+            @functools.wraps(f)
+            def wrapper(*args, **kwargs):
+                return f(*args, **kwargs)
+
+            wrapper('''), 'f(x: int, y: float)'],
+        [dedent('''
+            # identifier:D
+            def f(x: int, y: float):
+                pass
+
+            def wrapper(*args, **kwargs):
+                return f(*args, **kwargs)
+
+            wrapper('''), 'wrapper(x: int, y: float)'],
     ]
 )
 def test_wraps_signature(Script, code, signature):