Refactor Greatwall Protocol Architecture to Support Node Creation from Sa03

[flatFeather]

Pending Refinement

This issue is subject to further in-depth refinement before implementation.

What is the problem or limitation you are having?

The current architecture of the Greatwall protocol relies on maintaining a _currentNode and updating its value directly. This approach may be suboptimal for flexibility and maintainability.

Describe the solution you'd like

Refactor the architecture to allow nodes to be created either:

• Based on the previous node, or
• Directly from an Sa03 instance.

This would involve:

1. Adding a constructor to the Node class to enable the creation of a node from an Sa03 instance.
2. Updating the necessary logic in the protocol to adopt this new approach, removing the dependency on _currentNode and its value updates.

Acceptance Criteria

1. The protocol's functionality should remain consistent with its current behavior in t3-vault, specifically:
   • Key derivation.
   • Memorization assistant.
2. Unit tests should be implemented or updated to ensure the new architecture satisfies the above criteria.
3. Clear documentation of changes and their impact should be included.

Additional Notes

This issue should be revisited for a detailed refinement session to address any edge cases or additional implications before proceeding with development.