API attribute/call to get Issues by sort order in Boards

Description

Currently, there is no way from the API to get the sort/order of labeled issues. Users are able to sort issues in the Boards view but unable to pull the order via the API.

Proposal

Potentially include the issue ids/order in the Issue Board endpoint.

https://docs.gitlab.com/ee/api/boards.html#single-board

Potentially include the relative_position attribute from the issue so they can be 'sorted' by this once the data has been received.

Links / references

https://docs.gitlab.com/ee/api/issues.html

Internal Zendesk: https://gitlab.zendesk.com/agent/tickets/91650