Function render_ui_element_html 

fn render_ui_element_html(
    app_root: &Path,
    element_type: &str,
    input_type: Option<&str>,
    id: &str,
    name: &str,
    label: &str,
    value: &str,
    options_html: &str,
) -> Option<String>

Renders UI element HTML.