[ISSUSE #3925] shenyu sdk etcd watch

[misaya295]

about ISSUSE #3925

Make sure that:

• You have read the contribution guidelines.
• You submit test cases (unit or integration tests) that back your changes.
• Your local test passed ./mvnw clean install -Dmaven.javadoc.skip=true.

[codecov-commenter]

Codecov Report

Merging #4052 (bc0f9a0) into master (1a2648e) will decrease coverage by 0.07%.
The diff coverage is 16.12%.

@@             Coverage Diff              @@
##             master    #4052      +/-   ##
============================================
- Coverage     69.92%   69.84%   -0.08%     
+ Complexity     6833     6829       -4     
============================================
  Files           941      941              
  Lines         25745    25776      +31     
  Branches       2311     2312       +1     
============================================
+ Hits          18001    18003       +2     
- Misses         6340     6367      +27     
- Partials       1404     1406       +2     

Impacted Files	Coverage Δ
...ache/shenyu/register/instance/etcd/EtcdClient.java	68.29% <0.00%> (-31.71%)	⬇️
.../instance/etcd/EtcdInstanceRegisterRepository.java	64.86% <27.77%> (-35.14%)	⬇️
...shenyu/sync/data/consul/ConsulSyncDataService.java	78.33% <0.00%> (-1.67%)	⬇️
...henyu/admin/service/impl/UpstreamCheckService.java	62.66% <0.00%> (-1.34%)	⬇️

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