data certificate

This section is a work in progress.

Examples:

import { blob, Canister, ic, Opt, query } from 'azle/experimental';

export default Canister({
    // When called from a query call, returns the data certificate
    // authenticating certified_data set by this canister. Returns None if not
    // called from a query call.
    dataCertificate: query([], Opt(blob), () => {
        return ic.dataCertificate();
    })
});