Build treatment file visualizer

[JamesPHoughton]

When creating multi-stage treatments, or displaying pieces to different participants, the game stages description can become quite long, and may be susceptible to errors/typos. We should create a tool that allows the experiment designer to visualize the different components of their experiment as implemented, in a relatively easy way. It would be nice if we could use the actual experiment code, and display all participants' interfaces on the same screen, and scroll through time. Not sure if this is possible.

Kimberly has a draft of this in figma, lets start building it out. It may be helpful to move/replicate/extract some of the code from the validator in deliberation-empirica

[JamesPHoughton]

Splitting validator out into this issue: #722