(PDB-567 & PDB-191) Recreate hash for anonymization

This patch switches the hash anonymization to simply recreate it from the
contents of the new anonymized data instead. This gives us the ability to
provide reproduceability for hashes for comparison in tests.

This patch also removes any parsing of filenames we used to do for anon
meaning that only the data within a file is important removing the future
need to ever care about the name of the file.

Signed-off-by: Ken Barber <ken@bob.sh>