feat: Merge nacos-plugin PostgreSQL & Base Implementation

[WangzJi]

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What is the purpose of the change

This PR merges the PostgreSQL and Base datasource implementations from the nacos-plugin repository into the main
nacos repository. It also restores ConfigInfoAggrMapper and ConfigInfoAggrMapperByMySql which were previously deleted but are required dependencies for the merged code.

Brief changelog

1. Merge from nacos-plugin:

• Added postgresql dialect and mapper implementations.
• Added base mapper implementations to support the plugin architecture.
• Added DatabaseDialect interface and DatabaseDialectManager.

2. Restore Deleted Dependencies:
   Restored plugin/datasource/src/main/java/com/alibaba/nacos/plugin/datasource/mapper/ConfigInfoAggrMapper.java from git history.
   Restored plugin/datasource/src/main/java/com/alibaba/nacos/plugin/datasource/impl/mysql/ConfigInfoAggrMapperByMySql.java from git history.

Verifying this change

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[github-actions]

Thanks for your this PR. 🙏
Please check again for your PR changes whether contains any usage/api/configuration change such as Add new API , Add new configuration, Change default value of configuration.
If so, please add or update documents(markdown type) in docs/next/ for repository nacos-group/nacos-group.github.io

---

感谢您提交的PR。 🙏
请再次查看您的PR内容，确认是否包含任何使用方式/API/配置参数的变更，如：新增API、新增配置参数、修改默认配置等操作。
如果是，请确保在提交之前，在仓库nacos-group/nacos-group.github.io中的docs/next/目录下添加或更新文档（markdown格式）。

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
7 out of 11 committers have signed the CLA.

✅ wuchubuzai2018
✅ uselessbaozi
✅ onewe
✅ KomachiSion
✅ WangzJi
✅ caoyanan666
✅ silent-night-no-trace
❌ xiaoyonghaoe
❌ SweetWuXiaoMei
❌ henglianghu
❌ muzhi9018
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[wuyfee]

$\color{red}{FAILURE}$
DETAILS
✅ - docker: success
❌ - deploy (standalone & cluster & standalone_auth): failure
❌ - e2e-java-test (standalone & cluster & standalone_auth): skipped
❌ - e2e-go-test (standalone & cluster): skipped
❌ - e2e-cpp-test (standalone & cluster): skipped
❌ - e2e-csharp-test (standalone & cluster): skipped
❌ - e2e-nodejs-test (standalone & cluster): skipped
❌ - e2e-python-test (standalone & cluster): skipped
✅ - clean (standalone & cluster & standalone_auth): success

[wuyfee]

$\color{red}{FAILURE}$
DETAILS
✅ - docker: success
❌ - deploy (standalone & cluster & standalone_auth): failure
❌ - e2e-java-test (standalone & cluster & standalone_auth): skipped
❌ - e2e-go-test (standalone & cluster): skipped
❌ - e2e-cpp-test (standalone & cluster): skipped
❌ - e2e-csharp-test (standalone & cluster): skipped
❌ - e2e-nodejs-test (standalone & cluster): skipped
❌ - e2e-python-test (standalone & cluster): skipped
✅ - clean (standalone & cluster & standalone_auth): success