Create a UI for visualising all baselines and diffs

[gidztech]

The current HTML report shows the diff image when a test fails but it would be useful in a dev environment to see all visual baselines and any diffs that were generated after tests run locally. We could then have an option to interactivity rebase visuals.

To achieve this, we need a task to launch a Node server (like Express) via a new CLI option and an associated JS function returned from ConfigureLauncher