Paper Wallet API inconsistency

[SebastienGllmt]

Old API

takes a mnemonic, turns it into an entropy [u8] internally and uses that for paperwallet:unscramble https://github.com/input-output-hk/js-cardano-wasm/blob/e099e7e666805b5efb4eac14103b5dafdb1b73de/js/PaperWallet.js#L62 https://github.com/input-output-hk/js-cardano-wasm/blob/bd40ab0f8d6ae27998c7ef5125c8c5cbd109a285/wallet-wasm/src/lib.rs#L266

New API

takes the entropy directly as a [u8] https://github.com/input-output-hk/js-cardano-wasm/blob/1ce87da6ebee4f70cee7971eb79900fd83674f50/cardano-wallet/src/lib.rs#L1080

Problem

However, we have no way of turning type Entropy to [u8] in Yoroi as Entropy only exposes two methods: from_english_mnemonics and to_english_mnemonics.

This seems like a strange quirk in the API because of the following:

paper_wallet_scramble input: Entropy paper_wallet_scramble output: [u8] paper_wallet_unscramble input: [u8] paper_wallet_unscramble output: Entropy

This allows you to write the following code

    let bytes = paper_wallet_scramble(&test.entropy, &test.iv, test.password).unwrap();
    let bytes: Vec<u8> = JsValue::into_serde(&bytes).unwrap();
    let entropy = paper_wallet_unscramble(&bytes, test.password).unwrap();

However, in Yoroi we don't unscramble right after scrambling. These are done in different sessions. Maybe it makes more sense to have it consistently use Entropy for all these methods? We can also fix it with something like #57 but then we should probably also add a from_array function also which is a bit more complex (which is why it was left as a TODO https://github.com/input-output-hk/js-cardano-wasm/blob/1ce87da6ebee4f70cee7971eb79900fd83674f50/cardano-wallet/src/lib.rs#L89 )