feat: Properly encode/decode objects in gRPC calls

[erezrokah]

Example in https://github.com/cloudquery/plugin-sdk/blob/221cd418d88f479295895c34b9d51d478b77171f/internal/servers/plugin/v3/plugin.go#L42

[erezrokah]

Mostly resolved in #37