utils/scanpypi: use archive file name to specify the extraction folder

utils/scanpypi: use archive file name to specify the extraction folder

Some packages have archive name that is different from package name.
For example websocket-client's archive name is websocket_client-*.tar.gz.
scanpypi expects the temporary extract folder to be:

/tmp-folder/BR-package-name/PyPI-packagename-and-version

In the case of websocket-client package the real extraction folder
will be different from the expected one because of the '_' in the
archive file name.

Use archive file name instead of package name to specify the extraction
folder. As the version is already part of this file, we don't need to
specify it.

Bonus: remove obsolete "return None, None" as the function doesn't return
anything. OSError class doesn't provide "message" member, so replace it
with "strerror".

Fixes:
https://bugs.busybox.net/show_bug.cgi?id=11251

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Reviewed-by: Asaf Kahlon <asafka7@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>