sip_ua_helper: add sendOptions (#476)

Author: eschmidbauer

lib/src/sip_ua_helper.dart

@@ -14,6 +14,7 @@ import 'event_manager/event_manager.dart';
 import 'event_manager/subscriber_events.dart';
 import 'logger.dart';
 import 'message.dart';
+import 'options.dart';
 import 'rtc_session.dart';
 import 'rtc_session/refer_subscriber.dart';
 import 'sip_message.dart';
@@ -413,6 +414,10 @@ class SIPUAHelper extends EventManager {
     return _ua!.sendMessage(target, body, options, params);
   }
 
+  Options sendOptions(String target, String body, Map<String, dynamic>? params) {
+    return _ua!.sendOptions(target, body, params);
+  }
+
   void subscribe(String target, String event, String contentType) {
     Subscriber s = _ua!.subscribe(target, event, contentType);