Add delete logic for wp

To test at staging:

• Existing shop accounts

  • Use an existing shop account
  • Connect it from the cloud subscriptions page to an existing cloud account
  • Delete the cloud account
  • Assert in the wp admin users page that the user is gone and all their orders are assigned to user with ID 10795 i.e. 'account-creator@e.email'

• "new" shop accounts

  • Login with Murena ID at shop
  • Delete the corresponding Murena ID
  • Assert in the wp admin users page that the user is gone and all their orders are assigned to user with ID 10795 i.e. 'account-creator@e.email'