Fetch logs filtered by block number instead of block hash for FEVM

[nikugogoi]

Part of Investigate subgraph watchers lagging behind head

• Fetch logs by block number if upstream eth server is FEVM
  • In realtime sync, fetching logs by block hash has started taking longer time ~1min
  • Fetching logs by block number takes ~10sec
• Use node-fetch instead of ethersjs for eth_getLogs RPC method to fetch logs
  • ethersjs is taking longer time for eth_getLogs requests ~50sec