Private OperationHandler trait in public interfaces

[svix-jplatte]

Hi, currently the OperationHandler trait which is used in public interfaces can't be named from outside aide. It this intentional? I would like to wrap aide types in my own to restrict the operations / add extra stuff implicitly, but this is currently made much harder than it should be impossible due to this.

If you would accept a PR to export this trait (possibly with the method(s) #[doc(hidden)]), could you also make a branch for 0.12.x that I could backport this to (since we haven't upgraded to hyper 1.0 yet)?

[svix-jplatte]

Actually nevermind, I found AxumOperationHandler which I can use. It's not exactly intuitive because the top-level ApiMethodRouter constructors don't use that alias, but it works.