List out all "Layout Tabs" in the frontend

Assuming you have an 'entry', this should work:

{% for tab in entry.getFieldLayout().getTabs() %}
    <ul>
        <li>{{ tab.name }}
            <ul>
                {% for field in tab.getFields() %}
                    <li>{{ field.name }}</li>
                {% endfor %}
            </ul>
        </li>
    </ul>
{% endfor %}

if you don't need the fields then just:

{% for tab in entry.getFieldLayout.getTabs() %}
    <ul>
        <li>{{ tab.name }}</li>
    </ul>
{% endfor %}