RFC 354: CSS modularity for `wildcard` components

Created by: valerybugakov

RFC link.

Description

Before diving into the redesign, we should decide how to avoid adding new styles to the global stylesheet and reuse existing infrastructure effectively.

Definition of success

1. Modular CSS is enforced for new wildcard components.
2. It works well with existing global styles.

Notes

We need to keep in mind google for code initiative where additional bundle size will play significant role for SEO. Related further improvement via CSS code splitting.