Payments add modal form

* adds modal form for adding payments
* generalizes generic_table_form.html for table-form-like usage in modal_form.html
* adds css enhancements for focused input fields
* adds BaseModalForm as specification to BaseForm, which inherits the BSModalForm class as well
* adds translations

templates/modal/modal_form.html

@@ -15,6 +15,7 @@
     </div>
 
     <div class="modal-body">
+        <!--
         <article class="mb-5">{{form.form_caption}}</article>
         {% for field in form %}
         <div class="form-group{% if field.errors %} invalid{% endif %}">
@@ -25,6 +26,8 @@
             {% endfor %}
         </div>
         {% endfor %}
+        -->
+        {% include 'table/generic_table_form_body.html' %}
     </div>
     <div class="modal-footer">
         <button type="submit" class="btn btn-default">{% trans 'Continue' %}</button>

templates/table/generic_table_form.html

@@ -16,25 +16,7 @@
     {% endif %}
     <form method="post" action="{{ form.action_url }}">
         {% csrf_token %}
-        <table class="table">
-            <tbody>
-                {% for field in form %}
-                <tr title="{{ field.help_text }}" class="{% if field.errors %}error{% endif %}">
-                    <th scope="row" class="col-sm-3">
-                        <div>{{ field.label }}<span class="label-required">{% if field.field.required %}*{% endif %}</span></div>
-                        <small>{{ field.help_text }}</small>
-                    </th>
-                    <td class="col-sm-9">
-                        {{ field }}
-                        {% for error in field.errors %}
-                        <strong>{{ error }}</strong>
-                        {% endfor %}
-                    </td>
-                </tr>
-                {% endfor %}
-            </tbody>
-        </table>
-        <small>{% trans 'Fields with * are required.' %}</small>
+        {% include 'table/generic_table_form_body.html' %}
         <div class="row">
             <div class="col-md">
                 <a href="{{ form.cancel_redirect }}">

templates/table/generic_table_form_body.html

@@ -0,0 +1,20 @@
+{% load i18n %}
+        <table class="table">
+            <tbody>
+                {% for field in form %}
+                <tr title="{{ field.help_text }}" class="{% if field.errors %}error{% endif %}">
+                    <th scope="row" class="col-sm-3">
+                        <div>{{ field.label }}<span class="label-required">{% if field.field.required %}*{% endif %}</span></div>
+                        <small>{{ field.help_text }}</small>
+                    </th>
+                    <td class="col-sm-9">
+                        {{ field }}
+                        {% for error in field.errors %}
+                        <strong>{{ error }}</strong>
+                        {% endfor %}
+                    </td>
+                </tr>
+                {% endfor %}
+            </tbody>
+        </table>
+        <small>{% trans 'Fields with * are required.' %}</small>