Add support for Exclusion Lists for Java Linter

Currently the Java Linter for this extension is scanning all of my project's autogenerated code which is causing 1000+ problems to be reported. From a very thorough investigation both VSCode and this extension do not have any exclusion options for what directories/files are scanned by the Java Linter and reported in the Problems tab.

Environment

• Operating System: Windows 10 64-bit
• JDK version: JDK 11
• Visual Studio Code version: 1.66
• Java extension version: 1.7.0

Steps To Reproduce

1. Create a Java Project and have the extension installed.
2. Write example code that would get scanned by linter with problems.
3. Review extension settings and there is no option to add exclusion for the linter.

Current Result

Java Linter scans every directory and file for the entire project with no options for exclusions, turning off linter completely or other common options.

Expected Result

Java Linter should have settings in this extension for exclusions, turning off the linter, and using the .gitignore file as a default exclusion list.

Additional Informations

VSCode has said in other issues where this is brought up that this is the responsibly of the extensions to support exclusion lists for the Problems tab. Issue that is closed talking about this is found here: https://github.com/microsoft/vscode/issues/22289

Im Issue sind keine Implementierungsdateien oder Tests angegeben. Beginne damit, den Einstiegspunkt des Java-Linters und die Erweiterungseinstellungen zu finden, und verfolge dann, wie Diagnosen den Problems-Tab erreichen; fertig ist die Arbeit, wenn Ausschlüsse, Deaktivierung und die Filterung auf Grundlage von .gitignore für das gemeldete Szenario mit automatisch generiertem Code definiert und verifiziert sind.