fix: uppercase classes should be valid

[lianghx-319]

Change

• Make uppercase as validClassName

Why

Such class names will be filtered, but they are valid too.

<div class="Any-CSS-ClassName"></div>

[antfu]

I do not get what you are trying to achieve. Yes uppercase can be valid class names, but in Windi CSS all utils are lowercase and I didn't see how this helps

[lianghx-319]

For custom plugin, always lowercase limits how people implement there business usage. For me, I create a plugin generate T1-E-B component because the class name is defined in figma, there is no trade off to make it lowercase, and lowercase regexp filters my classNames. Eventually those classNames cannot passed to windicss processor.

[lianghx-319]

Another reason: windicss core doesn't ignore uppercase classNames, such lowercase limitations make different behavior between windicss ordinary usage and webpack-plugin uasge.