MLE-25666 Deferring construction of DatabaseClient

[rjrudin]

This is just scratching the surface - next step will be to modify GenericFileLoader to accept a DatabaseClientSupplier instead of a DatabaseClient. That will allow the commands for loading modules, data, and schemas to only construct a client when necessary instead of eagerly.

[github-actions]

Copyright Validation Results
Total: 4 | Passed: 4 | Failed: 0 | Skipped: 0 | at: 2025-12-01 21:05:20 UTC | commit: b10f2b0

✅ Valid Files

• ml-app-deployer/src/main/java/com/marklogic/appdeployer/command/modules/LoadModulesCommand.java
• ml-app-deployer/src/main/java/com/marklogic/appdeployer/command/plugins/InstallPluginsCommand.java
• ml-app-deployer/src/main/java/com/marklogic/appdeployer/command/security/InsertCertificateHostsTemplateCommand.java
• ml-javaclient-util/src/main/java/com/marklogic/client/ext/helper/DatabaseClientSupplier.java

✅ All files have valid copyright headers!