Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/urllib/response.pyi

@@ -0,0 +1,51 @@
+from email.message import Message
+from types import TracebackType
+from typing import IO, Any, BinaryIO, Callable, Iterable, List, Optional, Tuple, Type, TypeVar
+
+_AIUT = TypeVar("_AIUT", bound=addbase)
+
+class addbase(BinaryIO):
+    fp: IO[bytes]
+    def __init__(self, fp: IO[bytes]) -> None: ...
+    def __enter__(self: _AIUT) -> _AIUT: ...
+    def __exit__(
+        self, type: Optional[Type[BaseException]], value: Optional[BaseException], traceback: Optional[TracebackType]
+    ) -> None: ...
+    def __iter__(self: _AIUT) -> _AIUT: ...
+    def __next__(self) -> bytes: ...
+    def close(self) -> None: ...
+    # These methods don't actually exist, but the class inherits at runtime from
+    # tempfile._TemporaryFileWrapper, which uses __getattr__ to delegate to the
+    # underlying file object. To satisfy the BinaryIO interface, we pretend that this
+    # class has these additional methods.
+    def fileno(self) -> int: ...
+    def flush(self) -> None: ...
+    def isatty(self) -> bool: ...
+    def read(self, n: int = ...) -> bytes: ...
+    def readable(self) -> bool: ...
+    def readline(self, limit: int = ...) -> bytes: ...
+    def readlines(self, hint: int = ...) -> List[bytes]: ...
+    def seek(self, offset: int, whence: int = ...) -> int: ...
+    def seekable(self) -> bool: ...
+    def tell(self) -> int: ...
+    def truncate(self, size: Optional[int] = ...) -> int: ...
+    def writable(self) -> bool: ...
+    def write(self, s: bytes) -> int: ...
+    def writelines(self, lines: Iterable[bytes]) -> None: ...
+
+class addclosehook(addbase):
+    closehook: Callable[..., object]
+    hookargs: Tuple[Any, ...]
+    def __init__(self, fp: IO[bytes], closehook: Callable[..., object], *hookargs: Any) -> None: ...
+
+class addinfo(addbase):
+    headers: Message
+    def __init__(self, fp: IO[bytes], headers: Message) -> None: ...
+    def info(self) -> Message: ...
+
+class addinfourl(addinfo):
+    url: str
+    code: int
+    def __init__(self, fp: IO[bytes], headers: Message, url: str, code: Optional[int] = ...) -> None: ...
+    def geturl(self) -> str: ...
+    def getcode(self) -> int: ...