implementing feature for PartialEq and Hash with comparison of Sha256 hashed values for secrets

[kate-shine]

following advice in
#107 (comment)
added a feature that allows safer comparisons of secret values that should be resistant to timing attacks.

[ramosbugs]

thanks for the PR! I think cargo fmt is complaining about trailing whitespace

[kate-shine]

thanks for the PR! I think cargo fmt is complaining about trailing whitespace

Thanks, fixed! It might be a good idea to add a more opinionated rustfmt.toml to repo :) I didn't autoformate, because my rustfmt settings changed way more than what my contribution contained.

Thanks for great crates, by the way :) I'm currently using them for MS Entra and it's a super smooth experience.