Handles the cancellation of a campaign for the authenticated user.
This function performs several checks to ensure the campaign’s current state allows cancellation. If the campaign is eligible for cancellation, it updates the campaign’s status, initiates a background task to handle further operations, and provides an immediate response to the user.
Required request body data: campaign_uid: string - UID of campaign to cancel.
Returns: 200 - Success 400 - Bad Request (missing/bad values) 404 - Campaign not found 500 - Internal Server Error
No response body