Add @utility m*-xxx functionaliy

[stijns96]

I think I've seen it somewhere that this is not supported (yet), but I still want to point this out.

We often run into the situation that we want to add custom utilities for example margin or padding only. We now have to write every single possibility ourselves. That's why I'd like to see something like

@utilitie m*-container {
  margin-*: --spacing(2);
  // Open for suggestions here
}

I can imagine that this is hard to implement or maybe not even possible ATM, since you don't know what css property has to by applied.