Include shard_id in the log

[akiradeveloper]

No description provided.

[akiradeveloper]

To include shard_id in the log, we could use task_local (https://docs.rs/tokio/latest/tokio/task/struct.LocalKey.html).

We can give a context to task so inside task can have a reference to it. In this case, we can give shard_id as a context and all log macros (like info!) can refer to it. For convenience, we may need to implement special log macros that uses the context.

This way, obviously we can cover the internal threads but how to cover the gRRC request context is still unsure (at least for me).