Move comment for to use the delegated form template

opentech/apply/activity/templates/activity/include/comment_form.html

 <h4>Add communication</h4>
 <div class="wrapper wrapper--comments">
-    <form class="form form--comments" method="post" id="comment-form">
-        {% csrf_token %}
-        {{ comment_form }}
-        <button id="comment-form-submit" name="form-submitted" form="comment-form" class="button button--primary" type="submit" value="comment">Add message</button>
-    </form>
+    {% include 'funds/includes/delegated_form_base.html' with form=comment_form value='Comment' extra_classes='form__comments'%}
 </div>

opentech/apply/funds/templates/funds/includes/delegated_form_base.html

-<form class="form" method="post" id="{{ form.name }}">
+<form class="form {{extra_classes}}" method="post" id="{{ form.name }}">
     {% csrf_token %}
     <div class="form__item">
         {{ form }}