Update the template to expose the response context

[PatrickDinh]

Update the template to expose the response context:

• Add http status text to response context
• Instead of using HttpInfo class, expose the response context directly.
  The reason for this change is that in utils-ts, I found that I need access to the raw binary returned from the http call. Currently, there are methods such as rawTransactionWithHttpInfo that return the HttpInfo (wrapper of the ResponseContext), there are some limitations:
• when processing the response, if the response type isn't binary, the text is extracted from the response. This makes the binary stream unusable downstream. In utils-ts, I can't read the binary anymore.
• HttpInfo is just a thin wrapper around ResponseContext, I think we should just expose the ResponseContext and the consumers have full control of how they want to use it.