Function cmd_add_rectangle 

pub fn cmd_add_rectangle(
    path: &Path,
    component_name: &str,
    x1: &str,
    y1: &str,
    x2: &str,
    y2: &str,
    filled: bool,
    fill_color: &str,
    border_color: &str,
) -> Result<String, Box<dyn Error>>

Add a rectangle to a component.