Address review comments: Remove security notices from code generators, restore debugPrint statements, remove extra documentation files

Co-authored-by: animator <615622+animator@users.noreply.github.com>

lib/codegen/go/http.dart

@@ -89,8 +89,7 @@ func main() {
     HttpRequestModel requestModel,
   ) {
     try {
-      String result = "// SECURITY NOTICE: Please validate all inputs and URLs before use in production\n";
-      result += "// This code is generated for testing purposes\n\n";
+      String result = "";
       var hasBody = false;
 
       String url = requestModel.url;