doc: Improve Gradle plugin documentation (V24)

[mcollovati]

The Vaadin Gradle plugin does not read application.properties, so settings like vaadin.frontend.hotdeploy=true only take effect at runtime, not during Gradle builds. This was not documented, causing issues where vaadinPrepareFrontend would delete generated frontend files during IDE-triggered builds.

• Clarify that the Gradle plugin requires configuration via the vaadin {} block in build.gradle, not application.properties
• Add missing frontendHotdeploy to the plugin configuration options
• Add Gradle tab to the "Disabling the Pre-Compiled Bundle" section
• Document that vaadinPrepareFrontend is bound to processResources and runs on every compilation
• Add IntelliJ IDEA workarounds to Known Issues and run guide

Part of vaadin/flow#24108

[github-actions]

AI Language Review

The changes between the .old and .new versions primarily address clarifications and additions concerning IntelliJ IDEA and Gradle configurations for Vaadin projects. Here are some points that may require attention:

1. Clarification in Vaadin Plugin Configuration:

   • The note about vaadin.frontend.hotdeploy not being read from application.properties is important, but it could be emphasized more clearly to ensure users do not misunderstand where this property should be set. Consider making this a warning or a separate call-out for better visibility.

2. Additional Context for Known Issues:

   • In the Known Issues section, the workaround for IntelliJ IDEA and Gradle is well-described. Consider providing a brief explanation or a note about why IntelliJ's build and run actions default to using Gradle, as not all users may be familiar with this behavior.

3. Consistency in Terminology:

   • Ensure consistent usage of the term "hot deploy" across different sections. Sometimes it appears as "hotdeploy," which could create confusion.

Overall, the modifications and additions improve clarity regarding the setup and configuration of Vaadin projects in IntelliJ IDEA with Gradle. The new instructions are detailed and provide practical advice for avoiding common pitfalls related to IDE and build tool interactions.