Optimize read local cache file

[finefuture]

Refer: #455

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (05141fd) 26.67% compared to head (9980b0e) 26.67%.

Files	Patch %	Lines
...java/com/tencent/polaris/client/flow/BaseFlow.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #457   +/-   ##
=========================================
  Coverage     26.67%   26.67%           
  Complexity      595      595           
=========================================
  Files           183      183           
  Lines          7752     7752           
  Branches       1004     1004           
=========================================
  Hits           2068     2068           
  Misses         5421     5421           
  Partials        263      263           

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[chuntaojun]

https://github.com/polarismesh/polaris-java/blob/05141fd553d3d41461515a1c2742b46677c8b5fb/polaris-common/polaris-client/src/main/java/com/tencent/polaris/client/flow/BaseFlow.java#L234C1-L241C26

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现有代码已经有降级读取本地文件的逻辑，只需要移除 MessagePersistHandler调用 init 全量加载本地文件的逻辑即可

[finefuture]

https://github.com/polarismesh/polaris-java/blob/05141fd553d3d41461515a1c2742b46677c8b5fb/polaris-common/polaris-client/src/main/java/com/tencent/polaris/client/flow/BaseFlow.java#L234C1-L241C26

现有代码已经有降级读取本地文件的逻辑，只需要移除 MessagePersistHandler调用 init 全量加载本地文件的逻辑即可

readResourcesFromLocalCache这个方法最终是调用InMemoryRegistry的getInstances等方法, 此方法是从本地缓存读取数据, 并未从本地文件读取.此处需要增加一个降级处理: 当本地缓存不存在时从本地文件加载到缓存中.

[chuntaojun]

getInstances

嗯，对，这个是需要调整

[chuntaojun]

see this pr:#459