Web Dashboard: Hide blocks

From James Lord:

> The dashboard has a lot of stuff in it, and depending on the mode we’re using, some parts will be irrelevant. Would it be possible under Python control to hide blocks from the dashboard (and as a consequence if all the blocks in a group are hidden, the group vanishes too) leaving space for the blocks we actually want to see? It would tidy up the web dashboard too.This effect could be done by hiding the blocks in the configuration, but that would mean about 8 different configurations to maintain instead of one.