- [ ] I have searched the [issues](https://github.com/apache/incubator-dubbo/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [FAQ](https://github.com/apache/incubator-dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: all
* Operating System version: all
* Java version: all

### Steps to reproduce this issue
1. create two ReferenceConfig for same service with different configuration.
<dubbo:reference id="demoService" interface="com.alibaba.dubbo.DemoService">
</dubbo:reference>
<dubbo:reference id="demoServiceAsync" interface="com.alibaba.dubbo.DemoService" async="true">
</dubbo:reference>
2. startup the consumer application.
3. get the ConsumerModel from ApplicationModel.


Pls. provide [GitHub address] to reproduce this issue.

### Expected Result
ApplicationModel.allConsumerModels() should returns two ConsumerModel.

### Actual Result
ApplicationModel.allConsumerModels() only returns the first ConsumerModel.

If there is an exception, please attach the exception trace:

With future investigation, ReferenceConfig cannot put the second ConsumerModel as they are in same serviceName.

Also, this is the same issue for provider with below configuration.
<bean id="demoService" class="com.alibaba.dubbo.DemoServiceImpl"/>
<dubbo:service interface="com.alibaba.dubbo.DemoService" ref="demoService">
</dubbo:service>
<bean id="demoService2" class="com.alibaba.dubbo.DemoServiceImpl2"/>
<dubbo:service interface="com.alibaba.dubbo.DemoService" ref="demoService2">
</dubbo:service>

Here is my PR: https://github.com/apache/incubator-dubbo/pull/2582
public static boolean initConsumerModel(String serviceName, ConsumerModel consumerModel) {
        if (consumedServices.putIfAbsent(serviceName, consumerModel) != null) {
            logger.warn("Already register the same consumer:" + serviceName);
            return false;
        }
        return true;
    }
    public static void initProviderModel(String serviceName, ProviderModel providerModel) {
        if (providedServices.put(serviceName, providerModel) != null) {
            logger.warn("already register the provider service: " + serviceName);
            return;
        }
    }
   public static void addProviderInvoker(String serviceName,Invoker invoker){
       Set<Invoker> invokers = providedServicesInvoker.get(serviceName);
       if (invokers == null){
           providedServicesInvoker.putIfAbsent(serviceName,new ConcurrentHashSet<Invoker>());
           invokers = providedServicesInvoker.get(serviceName);
       }
       invokers.add(invoker);
   }
   public Set<Invoker> getProviderInvoker(String serviceName){
       Set<Invoker> invokers = providedServicesInvoker.get(serviceName);
       if (invokers == null){
           return Collections.emptySet();
       }
       return invokers;
   }
}