Implement method to retrieve deployment nounce

[idea404]

🌟 Feature Request

📝 Description

Implement a new method like wallet.getDeployNonce() that returns the deployment nounce.

🤔 Rationale

To get the deployment nounce for a deploy transaction now, you need to ask for the rawNonce for an account (the param is uint256, you need to pad the address with zeroes to the left) https://github.com/matter-labs/era-system-contracts/blob/3e954a629ad8e01616174bde2218241b360fda0a/contracts/NonceHolder.sol#L35

After you get the value it will be of form 2^128 * deploymentNonce + normalNonce. You then need to do the floored division (BigNumber.div(..)).

[danijelTxFusion]

After you get the value it will be of form 2^128 * deploymentNonce + normalNonce. You then need to do the floored division (BigNumber.div(..)).

This is already implemented in _splitRawNonce() which is used by getDeploymentNonce().

[danijelTxFusion]

Implented in both SDKs:

• zksync2-js v0.2.1: implementation, test
• zksync-web3 v0.16.0: implementation, test