Include mount destination information in extra_mounts

## Context

In the current backend code, extra_mounts uses the vfolder ID as a key and the mount_destination information as a value. However, when querying extra_mounts, the VirtualFolderNode is used, which does not provide the mount destination information.

## Acceptance criteria

- Modify the GraphQL query to include mount destination information for extra_mounts.
- Ensure that the mount destination information is accurately retrieved and displayed.

## Other information

When creating a service in the web UI, aliases can be used to set extra mounts. However, during updates, the original alias is not retrievable, leading to potential loss of alias information when editing other fields. This issue is related to https://lablup.atlassian.net/browse/FR-1347.

[View original message posted by Sujin Kim on 8/11/2025, 4:41:50 PM](https://teams.microsoft.com/l/message/19:3c0acc0825024daeb2211f55c4e7f4aa@thread.skype/1754898110038?parentMessageId=1754898110038)

JIRA Issue: BA-2104