API - Logout From Other Devices Endpoint #14

Goal: Implement an API endpoint to invalidate all user sessions, effectively logging the user out from all devices.

Background: For security purposes, we want to give users the ability to log out from all devices in case of suspicions about unauthorized access. This endpoint should invalidate all of the user's current sessions, requiring them to log in again on any device.

Tasks:

• Implement a new API endpoint that invalidates all user sessions when called.
• The endpoint should authenticate the user's current session to perform this action.
• Handle possible errors such as unauthenticated access or server errors.
• Write tests for the new endpoint.