Add ability to save to deployment cache

[iPaulPro]

🌟 Feature Request for hardaht-zksync plugins

💥 Plugin name

hardhat-zksync-deploy

📝 Description

When using hardhat-deploy I'm able to manually add deployments to the cache by doing something like:

const { save } = hre.deployments;

await save(contractName, {
  address: contractAddress,
  abi: abi,
});

The deployment-saver.ts file has similar functionality, but it's not exported for external use.

🤔 Rationale

When deploying contracts using a factory pattern, it's useful to be able to include those in the cache.