ENH: add __name__ attribue to ufuncs (#55)

Follow up to #44.

SciPy actually uses `__name__`, so add it.

Author: person142

numpy-stubs/__init__.pyi

@@ -620,6 +620,8 @@ little_endian: int
 tracemalloc_domain: int
 
 class ufunc:
+    @property
+    def __name__(self) -> str: ...
     def __call__(
         self,
         *args: _ArrayLike,

tests/pass/ufuncs.py

@@ -12,3 +12,4 @@
 np.sin(1, extobj=[16, 1, lambda: None])
 np.sin(1) + np.sin(1)
 np.sin.types[0]
+np.sin.__name__