Prefetch block and txs in historical processing instead of fetching them in events processing

[nikugogoi]

Part of Block processing optimizations

• Use ethersjs StaticJsonRpcProvider to avoid getNetwork calls
• Set gzip to true for network requests in ethersjs
• Prefetch required block and txs in historical processing and cache in memory for events processing
• TODOs to be fulfilled in follow-on PRs:
  • Use prefetched block data in subgraph block handler (not configured in sushiswap v3 subgraph)