Update UI gradle configuration and integration

[malliaridis]

Description

With the latest updates some of the functions used by the gradle configuration in the UI module are deprecated. This PR addresses these deprecations and updates the way it is included in the webapp (similar to js-client).

Solution

This PR replaces deprecations in the build.gradle.kts file of the UI module. It also relocates the JVM files from the custom-named desktop JVM sourceset to the default jvm sourceset.

Additionally, it updates the logic used for integrating the generated artifacts into the webapp during builds by following the same approach the js-client is included, with exposed configurations.

Tests

Only manual tests have been executed and confirmed that the project builds and the UI artifacts are included correctly.

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation)
• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide
• I have added a changelog entry for my change

[dsmiley]

I reviewed the build aspects. Thank you for addressing the TODO I put there to do this like js-client.

[malliaridis]

Thank you for addressing the TODO I put there to do this like js-client.

Thank you for providing both the todo and an example of how to do it. :D