Update from upstream

Our version of webgoat is now 9 months old, it's time to refresh from upstream.

I also fixed a few compilation errors with the (great) help of @tpresa, and backported them to https://github.com/WebGoat/WebGoat/pull/691

@asoborov I have tested the registry.gitlab.com/gitlab-org/security-products/analyzers/spotbugs:2 analyzer on this version, and it's generating the report as expected. I suggest to review this first, and use this version at your branching commit for !12 (closed) instead of removing problematic files.

Related issue: gitlab-org/gitlab#9816 (closed)