Highlight unconfigured masks in the frontend #36
Description
As of now, masks without proper filter configuration are shown as hardcoded red rectangles in the "state frame".
Highlighting that these masks are not "ready" yet should be a job for the frontend; in that way these highlights can be styled more easily. Moreover, this is a good excuse to let the frontend know the positions of the masks, which can be used for other features like showing mask names on hover etc.