[Feat] Gradle Build Chain Rework

[Bram1903]

Gradle Build Chain Rework

This PR overhauls the Gradle Build Chain by switching from Groovy to Kotlin DSL and introducing a buildSrc module. These changes enhance convenience and ease of maintenance, reducing duplicated configurations by consolidating them into convention plugins.

Tasks

• Kotlin DSL: Rewrote the build chain to use Kotlin DSL.
• Googler's Shadow Fork: Switched from johnrengelman's shadow plugin to googler's fork (See: Future home/support for Shadow? GradleUp/shadow#908)
• Version Injection: Added a task to inject the current version into the codebase as a static instance: ELVersions.
• Commit Hash: Added the current commit hash to the version.
• Non-Blocking Update Checker: Modified the update checker to be non-blocking.
• Update Checker Fixes: Ensured the update checker uses the tag_name field from the GitHub API instead of name.
• RunServer Improvement: Improved the current runServer task to apply a more advanced configuration, and to easily test Folia.

Global Versioning

This PR introduces global versioning, allowing the update of a single version in the root build.gradle.kts. This update is automatically propagated throughout the project. A new task in buildSrc injects an ELVersions class during compilation, holding the latest version using the PEVersion class. This class simplifies version comparison and management.

Update Checker Improvements

The update checker has been refactored to:

• Operate asynchronously, preventing it from blocking the main thread.
• Utilize the tag_name field from the GitHub API, ensuring compatibility when additional information is included in the title.