[aspnetcore] update or remove Swashbuckle.AspNetCore nuget package

Description / Suggestion

In the current server stub generated for aspnetcore / .NET Core 2.0, updating the nuget packages to their latest version available give code not compilable.
Regarding Swashbuckle, update to Swashbuckle.AspNetCore 4.x requires additionally to add Swashbuckle.AspNetCore.Annotations nuget package.
This one for the SwaggerOperation and SwaggerResponse attributes.

The Swashbuckle.AspNetCore is still necessary for the UseSwaggerUI() call in Startup class / Configure method.

Question: is this very necessary?

1. As this alternative implementation says, what's the point in creating the schema for Swagger UI from the code when the code was itself already created by the schema?

2. SwaggerResponseAttribute could easily get replaced by the ProducesResponseType as in MicrosoftDocs

3. The SwaggerOperationAttribute only repeats the name of the method. Is it very necessary?

More about Swashbuckle in their repo:
https://github.com/domaindrivendev/Swashbuckle.AspNetCore

Swagger-codegen version

version 2.4.0

Review the generated aspnetcore/.NET Core 2.0 server stub and its NuGet references, especially Swashbuckle.AspNetCore and Startup.Configure. Compare the required attributes and package versions, then verify the generated stub compiles after deciding whether to update or remove the dependency.