Enable Requesters to Close Their Active Requests

[junminahn]

Description:
Currently, there is no straightforward way to cancel active requests. As a result, the product team must rely on admins to manually reject these requests. This issue is especially problematic for public cloud product requests, where admins cannot review the create requests until the eMOU workflows are complete.

Technical Details:

• Add a new request status, CANCELLED to the database schema.
• Add document permission on request resources; cancel.
• Implement logic to remove associated entities for create requests when they are canceled:
  • Billing: Delete incomplete billing records associated with the request's license plate.
  • Tasks: Remove the SIGN_PUBLIC_CLOUD_MOU task linked to the request's EA ID.
• Add two new event types:
  • CANCEL_PUBLIC_CLOUD_REQUEST
  • CANCEL_PRIVATE_CLOUD_REQUEST
    These events will log cancellation actions.
• Update the requests panel to include filters for canceled requests.

Definition of Done:

• The original requester should have access to a "Cancel" button and be able to cancel their requests successfully.