Add module-info.java for modules

[lizongbo]

This pull request introduces module-info.java files across multiple modules in the repository, defining module names and dependencies, and exporting specific packages.

• Adds module-info.java files: New files have been added to druid-spring-boot-starter, druid-wrapper, druid-admin, and druid-demo-petclinic modules. Each file declares the module name and specifies required dependencies such as java.sql, spring.boot, spring.boot.autoconfigure, and spring.context. Additionally, each module exports its respective packages, making them available to other modules.
• Updates existing module-info.java: The module-info.java file in druid-spring-boot-3-starter has been updated to align with the naming convention of other modules and to refine the list of required dependencies and exported packages.

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