Need a new Github Action to test the CWS Docker image

[jamesfwood]

The current Github Actions compile and build CWS, and then run that code against a docker ES and MariaDb. There is currently no Action that builds the CWS Docker image, and then runs that image for a test.

This was discovered when I tried to run CWS in docker but the java version wasn't updated in the Dockerfile so the image itself failed to run. We need a test to actually test the CWS Docker image itself from here: install/docker/cws-image