Let users theme chats on a per-contqct basis

Per-contact chat themes:
Description: Chat personalization ans theming on a per-contact basis
Use case: Letting users personalize chats makes them more fun and engaging, especially for new users and the younger generations, while keeping the featureset up there with Signal, Telegram, and Facebook’s suite of apps.

Target user: Anyone who likes customizing things, teens, new users
Why this is important: It helps users feel comfortable in Status, and keeps the featureset on par with Signal and Telegram
Any other comments: It would be nice to let users share contact themes, but shouldn’t sync between the two users by default.