Make code insights user-resizable and reorderable

Created by: felixfbecker

The user should have freedom to reorder and resize code insights to create a dashboard. This should be persistable to user, org or global settings. This also allows us to give fixed default width and height to views, which makes the UI stable (in combination with #10375 (closed)).

First idea is to use CSS grid with native CSS resize, then a ResizeObserver to persist it. Could snap to grids with the CSS grid span keyword.