Code generated by roslibrust_codegen_macro relies on roslibrust_codegen

[Carter12s]

We're close to having the dependencies in the generated code correctly cleaned up. The last problem here is that a crate that wants to use the macro, can't just depend on the macro crate. It has to both depend on the macro crate and roslibrust_codegen for things to work out correctly.

The generated code contains chunks like:
#[serde(crate = "::roslibrust_codegen::serde")]

That don't resolve without roslibrust_codegen being listed as a dependency.

I'm not actually sure if there is a clean fix here? I'm not an expert on the rules of proc_macro crates and what they can re-export.

I think ideally roslibrust_codegen_macro would be able to be able to re-export the needed dependencies from roslibrust_codegen and be able to pass a flag into codegen so that the generated code uses "::roslibrust_codegen_macro::serde" instead?