Track form validation errors in Google analytics

We started tracking upload errors in eb264f34b7

This has been useful.

This commit adds tracking of other form validation errors, so we can
pick up if there’s a form field that’s causing people particular
trouble.

Also had to rewrite a very old test to look for page content in a
smarter way.

app/templates/components/list-entry.html

@@ -18,7 +18,7 @@
             </span>
           {% endif %}
           {% if field.errors %}
-            <span class="error-message">
+            <span class="error-message" data-module="track-error" data-error-type="{{ field.errors[0][0] }}" data-error-label="{{ field.name }}">
               {{ field.errors[0][0] }}
             </span>
           {% endif %}

app/templates/components/radios.html

@@ -9,7 +9,7 @@
       <legend class="form-label">
         {{ field.label.text|safe }}
         {% if field.errors %}
-          <span class="error-message">
+          <span class="error-message" data-module="track-error" data-error-type="{{ field.errors[0] }}" data-error-label="{{ field.name }}">
             {{ field.errors[0] }}
           </span>
         {% endif %}
@@ -50,7 +50,7 @@
      <legend class="form-label">
        {{ field.label.text }}
        {% if field.errors %}
-         <span class="error-message">
+         <span class="error-message" data-module="track-error" data-error-type="{{ field.errors[0] }}" data-error-label="{{ field.name }}">
            {{ field.errors[0] }}
          </span>
        {% endif %}
@@ -89,7 +89,7 @@
           {{ field.label.text }}
         {% endif %}
         {% if field.errors %}
-            <span class="error-message">
+            <span class="error-message" data-module="track-error" data-error-type="{{ field.errors[0] }}" data-error-label="{{ field.name }}">
               {{ field.errors[0] }}
             </span>
         {% endif %}

app/templates/components/textbox.html

@@ -24,7 +24,7 @@
         </span>
       {% endif %}
       {% if field.errors %}
-        <span class="error-message">
+        <span class="error-message" data-module="track-error" data-error-type="{{ field.errors[0] }}" data-error-label="{{ field.name }}">
           {% if not safe_error_message %}{{ field.errors[0] }}{% else %}{{ field.errors[0]|safe }}{% endif %}
         </span>
       {% endif %}