Configuration to Not Generate Defined Header Types #2027

Some Swagger specifications define named HTTP header types, a convenience where instead of having to find a header value string by the name and parse it into a specific type there is an object created and handle by azure-core for this. Unfortunately, in many SDKs this information is dropped when returning the response, instead of ResponseBase<Header, Body> only Response<Body> is returned. For cases like this we should have a configuration to not generate the header types at all, reducing package size and computation overhead of deserializing the HTTP headers into the header type.

Note: The configuration no-custom-headers partially handles this by providing Response<Type> APIs in the generated interface layer to remove the need to deserialize the headers type but this doesn't remove the header type from generation.