refact: enhance cache invalidation of the partition -> leader shard in ClientCache

[haohao0103]

Resolved the cache invalidation of the partition->leader shard in ClientCache

Purpose of the PR
close #2576

Main Changes
1、Set the initialization flag to false after resetting the cache, allowing reinitialization;
2、If the cache misses, the cache is updated with the results of the query from the PD.

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 2 lines in your changes missing coverage. Please review.

Project coverage is 4.54%. Comparing base (03b40a5) to head (2e77882).
Report is 2 commits behind head on master.

Files	Patch %	Lines
...va/org/apache/hugegraph/pd/client/ClientCache.java	0.00%	1 Missing ⚠️
.../java/org/apache/hugegraph/pd/client/PDClient.java	50.00%	1 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (03b40a5) and HEAD (2e77882). Click for more details.

HEAD has 5 uploads less than BASE

Flag	BASE (03b40a5)	HEAD (2e77882)
	6	1

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #2588       +/-   ##
============================================
- Coverage     52.49%   4.54%   -47.95%     
+ Complexity      586     479      -107     
============================================
  Files           643     621       -22     
  Lines         53393   50877     -2516     
  Branches       7018    6570      -448     
============================================
- Hits          28026    2312    -25714     
- Misses        22538   48379    +25841     
+ Partials       2829     186     -2643     

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