Implement generic_hash() function to support hashing algorithms (ZKP)

[devendran-m]

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As a developer building Zero Knowledge (ZK) software on Casper Network, I need cryptographic utilities to be implemented as host functions to ensure that the execution cost of cryptographic operations is efficient and manageable.

Acceptance Criteria:

• Implement a host function called generic_hash(input, type) that supports various hash algorithms.
• Currently supported algorithms:
  • HashAlgoType::Blake2b - utilizes the existing Blake2b implementation.
  • HashAlgoType::Blake3b - introduces the Blake3 library.
• Future support planned for additional algorithms such as sha256, keccak, and poseidon.
• The host functions should significantly reduce the execution cost, which in the current state (without host functions) can be excessive (e.g., running Risc0 VM proof verification for a simple sum of squares costs more than 6000 CSPR).

Benefit:

This feature will enable more efficient execution of ZK cryptographic operations like proof verifications, enhancing the usability and scalability of Casper-based applications without incurring prohibitive transaction costs.