Is your feature request related to a problem? Please describe.

In my current project, I need to consume two different swagger servers.
The problem is that both of them generate an api class that have the same name.
Example: Both generator PetAPI.Swift
This is a problem because Swift doesn't have built in namespaces or packages, so it fails to compile if it has the came class defined more than once, and the same to the file name.
This also happen with same model objects, but with modelNamePrefix, I added a different prefix to the models of each server, and in that way the collisions would be avoided.

Describe the solution you'd like

I propose to use the same solution that I used for models, but for the api classes, by adding apiNamePrefix.