feat: implement hardhat_metadata API endpoint

[kiriyaga-txfusion]

🌟 Feature Request

📝 Description

Returns an object with metadata about the instance of the Hardhat Network. This object contains:

• clientVersion: A string identifying the version of Hardhat, for debugging purposes, not meant to be displayed to users.
• chainId: The chain's id. Used to sign transactions.
• instanceId: A 0x-prefixed hex-encoded 32 bytes id which uniquely identifies an instance/run of Hardhat Network. Running Hardhat Network more than once (even with the same version and parameters) will always result in different instanceIds. Running hardhat_reset will change the instanceId of an existing Hardhat Network.
• latestBlockNumber: The latest block's number in Hardhat Network.
• latestBlockHash: The latest block's hash in Hardhat Network.
• forkedNetwork: An object with information about the forked network. This field is only present when Hardhat Network is forking another chain. Its fields are:
• chainId: The chainId of the network that is being forked
• forkBlockNumber: The number of the block that the network forked from.
• forkBlockHash: The hash of the block that the network forked from.

🤔 Rationale

To temporarily cache upgradable contracts for the development network in the hardhat-zksync-upgradable plugin, an endpoint is required to fetch the instanceId, which is unique to the network and changes with each run.