Add image visualization as type of script to generate testcase images

[eldering]

Currently we support having testcase images, but only loaded statically. We should have a new type of script to both be able generate those during import and also to generate them from team output, in case the visualization depends on the output and then also display those in the jury interface for visual comparison.

[meisterT]

I seem to remember that you have a prototype of this, is that correct?

[eldering]

I started looking into it, but no prototype yet. All I have is https://github.com/eldering/domjudge/tree/testcase-image-gen

[nickygerritsen]

Some points:

• We want to visualize after the result is known to the team (and jury)
• We want to run the visualizer on the judgehost

[meisterT]

In the discussion just now, it came up that this could a judgetask.