Allow border-* to match both color and size namesaces at the same time

[philipp-spiess]

Closes #16343

In v3, if you had a colors and borderWidth key that resolved to the same value, using the border-* utility would actually match create both rules: https://play.tailwindcss.com/Loe4Z1eKky?file=config

In v4, however, it currently only looks at the color and then ends. This PR changes it to be compatible with v3.

My main motivation for fixing this is that this is actually more like the @utility API works right now already where this would generate both rules: https://play.tailwindcss.com/bQNe7wXOJb?file=css

@utility border-* {
  color: --value(--color-*);
  border-width: --value(--border-width-*);
}

[philipp-spiess]

I wonder if we should audit all other utilities as well? This should probably be consistent for other things that have more than one overload, e.g. bg``stroke, from etc...

[philipp-spiess]

I'm going to close this issue for now since we aren't sure wether we want to make this change yet. It's unfortunate for backward-compatibility but we also think that it's kind-of unexpected since you're expecting most of these utilities to only set one value and if you are overloading the namespaces to have "side effects" (e.g. by having a color named default and a width named default) it's going to cause confusing in the stylesheet. You can still do that with @utility if you want to in user space.