[Color system] add missing variants

[danrosenthal]

This adds neutral surface variants

• surfaceNeutral (badge)
• surfaceNeutralSubdued (banner)

And depressed variants for buttons

• surfaceDepressed (outline button depressed state)
• actionSecondaryDepressed (secondary button depressed state)
• actionPrimaryDepressed (primary depressed state)
• surfaceCriticalSubduedDepressed (critical action list item depressed state, critical outline button depressed state)
• actionCriticalDepressed (critical button depressed state)

All light color scheme lightness configs are based on figma. Dark color scheme lightness configs were best guesses based on perceived patterns, and can be updated when we focus on dark mode.

Updated in color systems spreadsheet: https://docs.google.com/spreadsheets/d/1VtebqhKrVD9l90O4veYFcH86D9xiZxeuSt-IWTew6yc/edit#gid=568251708