bug #12267 [Form][WebProfiler] Empty form names fix (kix)

This PR was submitted for the master branch but it was merged into the 2.5 branch instead (closes #12267).

Discussion
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[Form][WebProfiler] Empty form names fix

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | none
| License       | MIT
| Doc PR        | none

When a Form had no name, the markup was broken in the profiler, making the form tree ugly. This pull request changes the output so that `(no name)` string is displayed when no form name was available.

Before:
![screenshot 2014-10-21 00 06 23](https://cloud.githubusercontent.com/assets/345754/4706329/d596a3ec-5883-11e4-8c67-44a7f357f3e1.png)

After:
![screenshot 2014-10-21 00 08 02](https://cloud.githubusercontent.com/assets/345754/4706359/122674c2-5884-11e4-8237-0177a590f2a0.png)

Commits
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6e9642a [Form][WebProfiler] Empty form names fix

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/form.html.twig

@@ -420,7 +420,7 @@
             {% else %}
                 <div class="toggle-icon empty"></div>
             {% endif %}
-            {{ name }}
+            {{ name|default('(no name)') }}
             {% if data.errors is defined and data.errors|length > 0 %}
             <div class="badge-error">{{ data.errors|length }}</div>
             {% endif %}
@@ -437,9 +437,9 @@
 {% endmacro %}
 
 {% macro form_tree_details(name, data, forms_by_hash) %}
-    <div class="tree-details" id="{{ data.id }}-details">
+    <div class="tree-details" {% if data.id is defined %} id="{{ data.id }}-details"{% endif %}>
         <h2>
-            {{ name }}
+            {{ name|default('(no name)') }}
             {% if data.type_class is defined %}
             <span class="form-type">[<abbr title="{{ data.type_class }}">{{ data.type }}</abbr>]</span>
             {% endif %}