[Dubbo-3370]support 'merge' attribute in @Reference and @Method

[shalk]

What is the purpose of the change

to support merge attribute in @Reference and @Method

example:

@RestController
public class MyController {
 
   @Reference(group = "merge,merge3",
            methods = {
                    @Method(name = "mergeResult", merger = "false", retries = 2)})
    MergeService mergeService;

   
    @GetMapping("/merge1")
    public List<String> test() {
        List<String> list = mergeService.mergeResult();
        return list;
    }
}

Brief changelog

1. add merger field in @Reference and @Method
2. add unit test in ReferenceConfigTest.java and MethodConfigJava to test getter, setter and construct from annotation
3. add unit test in AnnotationPropertyValuesAdapterTest.java check databind for merger
4. add unit test in ReferenceBeanBuilderTest.java to verify referencebean will contain merger info

Verifying this change

unit test :

• ReferenceConfigTest.java
• MethodConfigJavaTest.java
• AnnotationPropertyValuesAdapterTest.java
• ReferenceBeanBuilderTest.java

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[codecov-io]

Codecov Report

Merging #4619 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #4619      +/-   ##
============================================
- Coverage     64.17%   64.14%   -0.03%     
  Complexity      452      452              
============================================
  Files           768      768              
  Lines         32873    32869       -4     
  Branches       5181     5179       -2     
============================================
- Hits          21096    21085      -11     
- Misses         9361     9370       +9     
+ Partials       2416     2414       -2

Impacted Files	Coverage Δ	Complexity Δ
...ache/dubbo/config/spring/util/AnnotationUtils.java	39.21% <ø> (+1.47%)	0 <0> (ø)	⬇️
.../apache/dubbo/qos/protocol/QosProtocolWrapper.java	69.23% <0%> (-12.83%)	0% <0%> (ø)
...onfig/spring/extension/SpringExtensionFactory.java	80.48% <0%> (-4.88%)	0% <0%> (ø)
...bo/rpc/cluster/support/FailbackClusterInvoker.java	67.21% <0%> (-3.28%)	0% <0%> (ø)
...he/dubbo/registry/multicast/MulticastRegistry.java	67.87% <0%> (-1.81%)	0% <0%> (ø)
...g/apache/dubbo/registry/consul/ConsulRegistry.java	61.87% <0%> (-0.63%)	29% <0%> (ø)
.../java/org/apache/dubbo/config/ReferenceConfig.java	59.48% <0%> (-0.37%)	0% <0%> (ø)
.../apache/dubbo/remoting/transport/AbstractPeer.java	71.73% <0%> (+8.69%)	0% <0%> (ø)	⬇️

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[shalk]

@chickenlj could you review my code?

[shalk]

• @cvictory could you review my code ~

[CLAassistant]

All committers have signed the CLA.

[AlbumenJ]

This pull request may duplicated with #6092.

Please feel free to reopen if you have any question.