[Feature request]: Implement Constructable Stylesheets

[feerglas]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for an issue that matches the one I want to file, without success.

Request type

Request for enhancement of a component

It affects the following packages

Components

Functionality

Working with shadow root has it's drawbacks. On of them is duplication of styles and code.

Since CSSStyleSheet gained broad baseline support last year, it might be the time now to think about incorporating constructable stylesheets?

I have no concrete idea at which level this would be best integrated. I have the feeling that it would make most sense to integrate it at the lowest level possible (during/after bundling styles for the components) rather then leaving it up to consumers of the components.

https://developer.mozilla.org/en-US/docs/Web/API/CSSStyleSheet/CSSStyleSheet

I did not find anything in the issues and projects about this topic in this repo, so I thought I'll try to raise the topic :)

Link to design proposal file

No response

[feerglas]

Just noticed that styles already seem to be nicely constructed on a component level and that the issue of duplicated styles comes from my shaky integration testing with ssr ;) sorry for disruption guy 😇

[feerglas]

Once this PR get's merged, my problems might go away ;)
Shared and de-duplicated declarative styles utility