Prototype build with Javac support (08/11/2024)

Enable javac-based compilation in vscode-java with "java.jdt.ls.javac.enabled":"on" in your VS Code settings.
Requires running the extension with JDK 23 (set java.jdt.ls.java.home).

Built from:

• jdt.core.incubator: commit e114cb9
• jdt.ls: https://github.com/eclipse-jdtls/eclipse-jdt.ls/pull/3123 rebased on master
• vscode-java: redhat-developer#3558 rebased on master