Keystore kdf update

[Sajjon]

Checklist

• [x] I've run bundle exec fastlane tests from the root directory to see all new and existing tests pass
• [x] I've followed the Zhip code style enforced by Swiftlint and not introduced any new warning.
• [x] I've read the Contribution Guidelines
• [x] I've updated the documentation if necessary.

Motivation and Context

Zilliqa has changed algo for keystores, this updates Zesame to be using the new format.