[C#]Would be nice if code generated adds implementation for handling refresh tokens

Description

I think it would be nice if there was some sort of implementation in the generated code that handles Oauth2 Refresh Tokens. I am thinking there would be a configuration option that enables auto refresh, and the generated code would then check the expires time of the token and automatically call to refresh the auth token if it has expired and the configuration flag is set. Currently, I have two options to do this how the code is generated itself. I either have to add the code into the project before making the dll, or I have to manually check this info on the consumption side of things.

Swagger-codegen version

Master