Change CLI to use gRPC to interact with bots

[haseebrabbani]

When running CLI commands on bots (e.g. forta-agent run), the code from the bot is being directly imported by the CLI. To scale development of SDKs in other languages, we should update the CLI to not directly import the code but interact with it via gRPC. This would involve enabling the bots to start a gRPC server using the SDK (not the CLI)