UX change: Having user hold a certificate file instead of certificate hex string.

[zemse]

As of now, we are having hex strings as certificate representation.

This CertiDApp Improvement Proposal proposes the following UX:

1. Signers will sign a certificate and generate a certificate file.
2. Students will receive the certificate file and can hold it and need not register it on Ethereum Blockchain.
3. Students can also have the certificate registered on highly decentralized Ethereum Blockchain so only certificate hash would be enough to find the certificate.
4. To prove some verifier whether a student is verified, they either can send the file to the verifier or only the hash if the certificate is already registered on the smart contract. This way the candidate can also keep the certificate private by not registering it.

The changes are only required to be made on the UI and no change is needed on the smart contract.