Host email confirmations for upsell purchases and approvals

Currently, only guests receive email confirmations when an upsell is purchased or approved. Hosts only receive in-app notifications, which can be easily missed. Additionally, because the payment processing screen can take some time, hosts may not be able to wait for the in-app confirmation. This request is to add an email notification for the host to ensure they are immediately aware when an upsell transaction is completed and approved, regardless of whether they are watching the processing screen.