Function set_defined_name 

pub fn set_defined_name(
    wb: &mut WorkbookXml,
    name: &str,
    value: &str,
    scope: DefinedNameScope,
    comment: Option<&str>,
) -> Result<()>

Add or update a defined name in the workbook.

If a defined name with the same name and scope already exists, its value and comment are updated. Otherwise, a new entry is created.