v6: Restore 16px base font-size (#42119)

v6: Restore 16px base font-size (#42119)

* Restore 16px base font-size

* More

* Update docs CSS to account for font-size change

* Redo several components and tokens for font-size change

- Checks, radios, switches get new sizing to better match 16px base font-size. These are now way more consistent with one another.
- Updates other components to use new sizing as appropriate.
- Pagination now sized to match inputs/buttons.
- Clean up some other font tokens

* Fix

* fix code example