[JENKINS-55049] Avoid NumberFormatException when a symlink is used as… (#3790)

* [JENKINS-55049] Avoid NumberFormatException when a symlink is used as artifact
- display a "0 B" instead of nothing + exception thrown

* Different approach to cover all the specific cases of Long.decode

* Update core/src/main/java/hudson/model/Run.java

Co-Authored-By: Wadeck <Wadeck@users.noreply.github.com>

* Add test for length check