Introduce Keccak 256 hashing algorithm

[thil4n]

Problem

Keccak-256 is widely used in blockchain related technologies and currently Ballerina crypto module does not provide the Keccak-256 algorithm.

Proposed Solution

Extend the Ballerina crypto module to add the support for Keccak-256 hashing.

Alternatives

No response

Version

No response

[thil4n]

@MohamedSabthar Feature implemented and merged. ballerina-platform/module-ballerina-crypto#578

[MohamedSabthar]

Fixed via: ballerina-platform/module-ballerina-crypto#578