[Feature] 请求支援国产数据库达梦

### Feature Description (功能描述)

现在很多项目中对国产化要求越来越多，其中一项就是达梦数据库的支持，请求支援loader导入的数据的时候，支援达梦数据库，这样不用单独定制loader包

Start by locating the loader import entry point and the existing database integrations in the repository. Compare how supported databases are configured and used, then determine what Dameng support would require. Done means loader imports work with Dameng without a separately customized loader package, with the relevant coverage verified.

Written by the indexing model from the issue text.