forked from loafle/openapi-generator-original
* [typescript-rxjs] restore prototype inhertance - previously clone() and its clients in the BaseAPI class were generic - with removal of the generic argument, these methods became unavailable to the API classes inheriting from BaseAPI - original generic was imprecise, as these are not statics - return type of `this` is the correct notation * [typescript-rxjs] Chery-pick from #5465 by @denyo - this is done to prevent the changes slated for 5.0 from conflicting - apply destructuring changes from - denyo:feature/rxjs-statuscode-and-progress@673d67c