#2418 updating jpackage config (#2713)

# Description

Updating the `jpackage` configuration in our build.gradle and CI to
enable installation of the app on multiple OSs

Closes #2418 

## Checklist

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have performed a self-review of my own code
- [x] I have attached images of the change if it is UI based
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] If my code has heavily changed functionality I have updated
relevant docs on [Stirling-PDFs doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
- [x] My changes generate no new warnings
- [x] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

.gitignore

@@ -21,6 +21,7 @@ pipeline/finishedFolders/
 customFiles/
 configs/
 watchedFolders/
+clientWebUI/
 !cucumber/
 !cucumber/exampleFiles/
 !cucumber/exampleFiles/example_html.zip