move to java 11

[dterrybd]

This work moves Detect to using Java 11 as the minimum version.

The changes to the actual product are very simple, just update the build.gradle lines and Detect builds with Java 11 just fine. This is pretty much expected given 11 didn't remove anything we were using in the code base.

The majority of changes then fall into two categories:

1. Updating Dockerfiles to install Java 11 JREs instead of Java 8 ones as those no longer work
2. Altering the version number of built images so the tests don't run agains the previous images.