Add per-parameter "visible in symbol" flag for KiCad EDA export (#1444)

* Add per-parameter "visible in symbol" flag for KiCad EDA export

Introduce a nullable tri-state eda_symbol_visibility on part parameters
that drives the KiCad field's "visible" flag in the EDA HTTP-library API
response. This is independent of the existing eda_visibility, which only
controls whether the parameter is exported as a field at all.

When the per-parameter flag is null, the new system default
KiCadEDASettings::defaultParameterSymbolVisibility applies. Both default
such that exported parameter fields keep their previous behavior
("visible": "False"), so the change is backward compatible.

- Entity: eda_symbol_visibility column + accessors, with matching
  serialization groups and a multi-platform migration
- Form: second TriStateCheckboxType, shown for part parameters only
- KiCadHelper: resolve the flag (explicit, else system default) and pass
  it to createField()
- Settings: defaultParameterSymbolVisibility (default false)
- Templates: new eye-icon column in the specifications table
- Translations (en) + tests

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Fixed message ids

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Jan Böhmer <mail@jan-boehmer.de>

templates/parts/edit/_specifications.html.twig

@@ -15,6 +15,7 @@
             <th>{% trans %}specifications.text{% endtrans %}</th>
             <th>{% trans %}specifications.group{% endtrans %}</th>
             <th title="{% trans %}specifications.eda_visibility.help{% endtrans %}"><i class="fas fa-bolt fa-fw"></i></th>
+            <th title="{% trans %}specifications.eda_symbol_visibility.help{% endtrans %}"><i class="fas fa-eye fa-fw"></i></th>
             <th></th>
         </tr>
         </thead>

templates/parts/edit/edit_form_styles.html.twig

@@ -83,6 +83,9 @@
         {% if form.eda_visibility is defined %}
         <td class="text-center">{{ form_widget(form.eda_visibility) }}</td>
         {% endif %}
+        {% if form.eda_symbol_visibility is defined %}
+        <td class="text-center">{{ form_widget(form.eda_symbol_visibility) }}</td>
+        {% endif %}
         <td>
             <button type="button" class="btn btn-danger btn-sm order_btn_delete position-relative {% if form.parent.vars.allow_delete is defined and  not form.parent.vars.allow_delete %}disabled{% endif %}"
                     {{ collection.delete_btn() }} title="{% trans %}orderdetail.delete{% endtrans %}">