Cleanup interface for 4.1.x build

Feedback for mobile going forward

Background colours

• Use primary background colour for the main background
• Use secondary background for any surfaces

Consistant spacing

• Desktop uses 20px or 40px. Suggest mobile to use half of those values.

Theming confusion

• Lots of references to ThemedStyle...,CS..., Styles... - Lets pick one and use it or document when to use one over the other
• backgroundPrimary is a different naming convention to primaryTextColor. Need consistency

DRY for settings

• Lots of repeated code in settings. We should have re-usable components here.

Naming conventions

• Do not use New as a class name

Linting

• Prettier needs implementing