[IntelliSense] Show IntelliSense for blocklisted classes

[mrmckeb]

First, I'm very happy to make the PR for this one.

In our case, we separately generate a "global" CSS file that includes common utilities for our micro-frontend apps, to prevent duplication.

Each micro-frontend build and deploys its own CSS. They're told to omit that "global", which works well, but the blocklisted classes. Example below:

@source not inline("{{p,m,gap}-{0..8},flex,grid,sr-only}");

I have a workaround for now, which is to have two CSS files - one for the editor, and one that's includes this config but is excluded in the plugin's configuration.