Add Generic Type for Simple Cache Map

[ZhangShenao]

Please do not create a Pull Request without creating an issue first.

What is the purpose of the change

Add Generic Type for Simple Cache Map

Brief changelog

Add Generic Type for Simple Cache Map

Verifying this change

Follow this checklist to help us incorporate your contribution quickly and easily:

• Make sure there is a Github issue filed for the change (usually before you start working on it). Trivial changes like typos do not require a Github issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Format the pull request title like [ISSUE #123] Fix UnknownException when host config not exist. Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add integration-test in test module.
• Run mvn -B clean package apache-rat:check findbugs:findbugs -Dmaven.test.skip=true to make sure basic checks pass. Run mvn clean install -DskipITs to make sure unit-test pass. Run mvn clean test-compile failsafe:integration-test to make sure integration-test pass.

[codecov-commenter]

Codecov Report

Merging #8812 (f034889) into develop (34bbd38) will increase coverage by 0.08%.
The diff coverage is 69.23%.

@@              Coverage Diff              @@
##             develop    #8812      +/-   ##
=============================================
+ Coverage      43.25%   43.33%   +0.08%     
- Complexity      4713     4716       +3     
=============================================
  Files            904      904              
  Lines          32504    32527      +23     
  Branches        3751     3754       +3     
=============================================
+ Hits           14058    14095      +37     
+ Misses         17095    17079      -16     
- Partials        1351     1353       +2     

Impacted Files	Coverage Δ
.../alibaba/nacos/common/remote/client/RpcClient.java	35.30% <0.00%> (ø)
...ice/impl/PersistentClientOperationServiceImpl.java	55.62% <69.56%> (+2.34%)	⬆️
...m/alibaba/nacos/common/cache/impl/SimpleCache.java	100.00% <100.00%> (ø)
...thcheck/v2/PersistentHealthStatusSynchronizer.java	100.00% <100.00%> (ø)
...os/client/auth/ram/identify/CredentialService.java	78.84% <0.00%> (-3.85%)	⬇️
.../core/v2/event/publisher/NamingEventPublisher.java	75.00% <0.00%> (-1.25%)	⬇️
...os/common/trace/publisher/TraceEventPublisher.java	72.83% <0.00%> (-1.24%)	⬇️
...m/alibaba/nacos/core/remote/ConnectionManager.java	37.86% <0.00%> (-1.19%)	⬇️
...va/com/alibaba/nacos/naming/misc/SwitchDomain.java	52.77% <0.00%> (+0.55%)	⬆️
...a/nacos/core/remote/control/TpsMonitorManager.java	55.84% <0.00%> (+1.29%)	⬆️
... and 2 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ff336d9...f034889. Read the comment docs.