Introduce emoji avatar creation screen. Subsequent diffs will integrate this into the profile navigator/navigating to this screen. This diff is purely just a UI/UX diff for the avatar creation screen, and the next diff will handle the behavior/UX when a user tries to save their new emoji avatar
[[ https://www.figma.com/file/a1nkbWgbgjRlrOY9LVurTz/Comm-%2F-Desktop-app?node-id=11195-257098&t=kzywCIg8xnU6ukPx-4 | Link to figma ]]
Design:
{F464434}
Depends on D7353