PLATFORM: Add email preferences UI

Description

Users should be able to opt in or out of email updates. They should be able to manage this from user settings screen.

Solution

• Add a section named "Email Preferences" under user settings
• Add these options:

Marketing: Receive news about product updates Activity: Receive updates about your workspaces and app specific events Critical: Receive time specific or critical updates

• Add a save button to the bottom right

Feel free to update the description. It is not very perfect.

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