updated tests for rust

Author: badnikhil

lib/codegen/rust/actix.dart

@@ -39,9 +39,9 @@ String kTemplateParams = """
     let payload = serde_json::json!({{body}});
 
 """;
-
-  String kTemplateHeaders =
-      """\n        {% for key, val in headers -%}.insert_header(("{{key}}", "{{val}}")){% if not loop.last %}{{ '\n        ' }}{% endif %}{%- endfor -%}""";
+String kTemplateHeaders =
+    """
+\n    {% for key, val in headers -%}request = request.insert_header(("{{key}}", "{{val}}"));{{ '\n    ' }}{%- endfor -%}""";
 
   String kTemplateFormHeaderContentType = '''
 multipart/form-data; boundary={{boundary}}''';

lib/codegen/rust/hyper.dart

@@ -23,6 +23,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
   final String kTemplateParams = """
     {% for key, values in params %}{% for val in values %}
     url.query_pairs_mut().append_pair("{{ key }}", "{{ val }}");{% endfor %}{% endfor %}
+    
 """;
 
   final String kTemplateMethod = """