console: add support for %c style formatter in console.log()

[humphd]

Node's console currently supports a number of formatters, s, j, d, o, O, i, f. However, it doesn't support %c:

> console.log('%cHello World', 'color:green; background:yellow;')
%cHello World color:green; background:yellow;

The same code in Safari, Firefox, and Chrome does this:

The Console spec doesn't give a ton of help on what %c should do, other than to say that it "Applies provided CSS."

Obviously there are aspects of this that don't make sense in the terminal vs. a browser, but perhaps some of it does? It would be nice if node's console could do more than ignore %c.

Apologies if this has come up in the past and been rejected. I wasn't able to find a previous discussion.

[devsnek]

Technically possible but we'd need to bring in a CSS parser, map all the ANSI stuff, etc...

What if we just strip out %c formatting entirely:

> console.log('%cHello World', 'color:green; background:yellow;')
Hello World

[jasnell]

For now, I'd say stripping out the %c formatting is the better approach.

[jcbhmr]

Is there any interest in pursuing this to make CSS %c colors work in Node.js? Deno has this support, so it's already "been done" in the sense that there's public MIT-licensed code that could be used as a how-it-was-already-done example: https://github.com/denoland/deno/blob/306b51d7728a6e28461171d3332a0b3aa8545a6e/ext/console/01_console.js#L2821-L2926

I think that what would need to change is here: https://github.com/nodejs/node/blob/main/lib/internal/util/inspect.js#L2263