Seeing as old versions of the hash may be in the users config, add a
StorageVersion field to the office config Passwords section which
defaults to 0 to indicate the old hash is in use.
Try the old varient when StorageVersion is 0. When a new encoded master
password it set write StorageVersion of 1 to indicate a new hash is in
use and use the new style when StorageVersion is 1.
Change-Id: I3174c37a5891bfc849984e0ec5c2c392b9c6e7b1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/131947
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>