refactor: reduce event bus provider boilerplate code

[links234]

This is a pure refactor PR (no functional changes expected) to reduce boilerplate code for Storage Hub actors framework (event bus provider).

For more details please read README.md inside actors-derive crate.

[snowmead]

We should have module/macro level documentation so that we could hover over the macros and see directly the documentation on how to use them. It is much simpler for developers.

[snowmead]

Will approve when we add module/macro level documentation for ease of development