Debugger should use project's Java runtime to launch application

[fbricon]

Debugger uses the java.home version used to start jdt.ls, instead of the project's target JDK.

Environment

• Operating System: MacOS
• JDK version: any
• Visual Studio Code version: 1.41.x or 1.42.0-insider
• Java extension version: 0.56.0
• Java Debugger extension version: 0.24.0

Steps To Reproduce

1. Have java.home to point to JDK 1.8
2. Have Java 11 installed in /Library/Java/JavaVirtualMachines/ on a Mac, or use vscode-java 0.56.0 and set

"java.configuration.runtimes": [
        {
            "name": "JavaSE-11",
            "path": "/path/to/jdk-11"
        },

3. create a Maven project targeting Java 11 (set <maven.compiler.source> and <maven.compiler.target> to 11)
4. run a main class

Current Result

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/acme/GreetingResource has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

Expected Result

Program should run using the JDK version set for the given project, without any errors

[akaroml]

This requires the debugger to follow the target platform specified in the project. @testforstephen please help prioritize this.

[akaroml]

Related PR eclipse-jdtls/eclipse.jdt.ls#1307