feat: meta storage firestore

[bestmike007]

What changed? Why?

• Added GCP emulators dockerfile and wrapper scripts
• Implemented firestore backed block storage and event storage
• Added integration tests

How did you test the change?

• [x] unit test
• [x] integration test
• [x] functional test
• [x] adhoc test: configure to use firestore emulator to start server, and use admin cli to backfill some blocks, and use sdk cli to fetch blocks