Improve block explorer handling of verification in Prividium mode

[tomimor]

🌟 Feature Request

📝 Description

Right now, the contract verifier is expected to be public, and the prividium block explorer performs API calls directly to the contract verifier.

For further improvement on access control, we should aim to have the explorer frontend going through the explorer API to interact with the contract verifier to add the ability to enforce authorization and permissions rules for verification.

🤔 Rationale

This architectural improvement will:

• Enable implementation of authorization and permission controls for verification
• Allow for future enhancements to verification workflows and access patterns.