Add ContentStream property to ApiResponse

Author: alec-petersen

modules/openapi-generator/src/main/resources/csharp/libraries/generichost/ApiResponse`1.mustache

@@ -33,6 +33,11 @@ namespace {{packageName}}.{{clientPackage}}
         /// The raw content of this response.
         /// </summary>
         string RawContent { get; }
+        
+        /// <summary>
+        /// The raw binary stream (only set for binary responses)
+        /// </summary>
+        public System.IO.Stream? ContentStream { get; }
 
         /// <summary>
         /// The DateTime when the request was retrieved.
@@ -81,6 +86,11 @@ namespace {{packageName}}.{{clientPackage}}
         /// </summary>
         public string RawContent { get; protected set; }
 
+        /// <summary>
+        /// The raw binary stream (only set for binary responses)
+        /// </summary>
+        public System.IO.Stream? ContentStream { get; protected set; }
+
         /// <summary>
         /// The IsSuccessStatusCode from the api response
         /// </summary>