[data grid] Unify spacing #47119
Description
4. Theming – Spacings
The spacing theming has no clear or direct impact. Adjusting it primarily leads to inconsistent spacing in MenuItems within MenuList or in other features, which makes the layout appear broken.
Summary of Requests
- 📖 Clear, centralized theming documentation explaining the impact of each token and attribute
- 🏷 Consistent naming of theming properties and slots
- 🎯 Centralized icon slots without heavy overwriting