Move calibration to web and tidy

If we're going to add more calibration requirements (see https://github.com/DiamondLightSource/I15J_RCS/issues/11) we're going to need to give more feedback:

* The UI should guide you through the process more e.g. tell you what to click without having to refer to the docs
* The UI should show you where you have clicked (and maybe let you reselect these)

As the docs already mention it would be cleaner if the UI was exposed over a webpage and you could modify it whilst running. If we're going to make the changes above then we should do this first.

## Acceptance Criteria
* There is a web UI for calibrating the algorothm
* This UI gives feedback on where you have selected