Missing properties hide_backlog_list and hide_closed_list in UpdateIssueBoardOptions

The current UpdateIssueBoardOptions and IssueBoard structs do not support hiding the backlog or closed lists on an issue board. According to the GitLab API documentation, hide_backlog_list and hide_closed_list are valid boolean attributes for updating a board.

Expected Behavior

Developers should be able to pass HideBacklogList and HideClosedList as pointers to booleans when using the UpdateIssueBoard method, and the returned IssueBoard struct should accurately reflect these states.

Current Behavior

The fields are completely missing from UpdateIssueBoardOptions and the base IssueBoard model, making it impossible to manage these board settings via the Go SDK.

Possible Solution

1. Add HideBacklogList and HideClosedList to UpdateIssueBoardOptions as *bool with json and url tags.
2. Add HideBacklogList and HideClosedList to the IssueBoard struct as bool with json tags.
3. Update relevant unit tests to assert the parsing of these new fields.