chore:no empty

[CommanderStorm]

This removes all instances of empty from our API as noticed in #219 (comment)

Try to avoid Empty as changing it to an actual Request payload is not compatible on the wire format and might cause incompatibility if we want to extend this later on.

Because field types are also used to determine when the receiver ends a field, changing field types across versions without carefully checking for compatibility can also cause problems. There are many specific rules about how to change field types, but a good standard is to avoid ever changing the wire type of any field. If you’re in a situation where you need to change a field type, the best path forward is to deprecate the existing field and put the new information into a new field.

https://earthly.dev/blog/backward-and-forward-compatibility/