Fix incorrect usage of AnyStr (#1215)

* Fix incorrect usage of AnyStr

- sqlite3 was using Union[bytes, AnyStr], which doesn't make sense
- The urllib functions I changed accept either bytes or str for their "safe"
  argument
- Also added supports for PathLike to pstats
- Remove some unused imports of AnyStr

* pstats: python 2 accepts unicode

stdlib/3/subprocess.pyi

@@ -2,7 +2,7 @@
 
 # Based on http://docs.python.org/3.6/library/subprocess.html
 import sys
-from typing import Sequence, Any, AnyStr, Mapping, Callable, Tuple, IO, Optional, Union, List, Type, Text
+from typing import Sequence, Any, Mapping, Callable, Tuple, IO, Optional, Union, List, Type, Text
 from types import TracebackType
 
 _FILE = Union[int, IO[Any]]