WIP: Firehose and graph-node integration

[Dentosal]

This is heavily in-progress. See https://github.com/FuelLabs/fuel-core/issues/1537 for the tracking issue.

This PR adds:

• protobuf defintions of Fuel blocks and everything inside them
• A possibility to print new blocks to stdout when they're created
• firehose-fuel component that reads those messages, essentially a fork of https://github.com/streamingfast/firehose-acme for fuel-core

[ra0x3]

Subscribing :)

[Dentosal]

Migrating to https://github.com/FuelLabs/fuel-subgraph/pull/8