platform independent script to verify sha256 checksums

[KASR]

feat: add python script to verify the file hashes, the goal is to be platform independent

the output is a table with the filename, valid checksum (if the hash matches), and file missing (if the file is not found).

[prusnak]

There is no reason to overengineer the script with psutil. There is no reason not to read in chunks. Please keep the script simple.

[KASR]

There is no reason to overengineer the script with psutil. There is no reason not to read in chunks. Please keep the script simple.

ok I've updated the script accordingly. the file is now always read in chunks.