storage_stats: Fix parsing padded deb822 columns

aptly seems to export its Release files with padding between columns to align them, e.g.:

03dbf158875ca31ec49be21ce8f8b5b0 13453697 development/binary-amd64/Packages
142723c7e10f049964bb791ff4458fe9  3961225 development/binary-amd64/Packages.gz
e5901baeb150db5d020a5e3bcd87d166      174 development/binary-amd64/Release

instead of the previous:

03dbf158875ca31ec49be21ce8f8b5b0 13453697 development/binary-amd64/Packages
142723c7e10f049964bb791ff4458fe9 3961225 development/binary-amd64/Packages.gz
e5901baeb150db5d020a5e3bcd87d166 174 development/binary-amd64/Release

This broke parsing the files, since it would previously split by a single space, resulting in several "columns" that were entirely empty.

https://phabricator.apertis.org/T9101

Signed-off-by: Ryan Gonzalez ryan.gonzalez@collabora.com