Function apply_task_edit 

pub fn apply_task_edit(
    queue: &mut QueueFile,
    done: Option<&QueueFile>,
    task_id: &str,
    key: TaskEditKey,
    input: &str,
    now_rfc3339: &str,
    id_prefix: &str,
    id_width: usize,
    max_dependency_depth: u8,
) -> Result<()>