Era test node does not implement some hardhat endpoints, in eth namespace

[vbar]

🌟 Feature Request

📝 Description

Specifically,

eth_coinbase

• implemented to fail
• looking at https://docs.zksync.io/build/developer-reference/ethereum-differences/evm-instructions#coinbase , it could be implemented to return bootloader address

eth_mining

• implemented to fail
• could be implemented to return false (with synchronization), as the test node only mines new blocks in a critical section

eth_pendingTransactions

• not implemented
• could be implemented to return an empty list

eth_sign

• not implemented
• the API is deprecated as unsafe

eth_signTypedData_v4

• not implemented
• Ethereum-specific

eth_subscribe

• not implemented
• Ethereum-specific

eth_unsubscribe

• not implemented
• requires eth_subscribe

[MexicanAce]

If there are specific endpoints we need to implement, it will be easier to track each one as their own GH issue