x-collapse should use overflow:clip with optional overflow-clip-margin

[simonferndriger]

Currently, x-collapse is using overflow:hidden which cuts off any horizontal shadow. If it would be using overflow:clip with an additional overflow-clip-margin (which should be configurable), the horizontal shadow would persist.

Merry Xmas 🎄

[grey4owl]

I made a PR (#3949) with improvements and added overflow: clip instead of hidden. You can add overflow-clip-margin using CSS to the given element with the x-collapse attribute..