Show form elements for templates and folders

This commit adds:
- checkboxes to let you select a template or folder
- radio buttons to let you select where to move those template(s) and/or
  folder(s) to

It only does the `get` part of this work; handling the `post` and
calling API will be done in a subsequent commit.

app/templates/components/checkbox.html

@@ -4,12 +4,7 @@
   width='2-3'
 ) %}
   <div class="multiple-choice">
-    <input
-      id="{{ field.id }}" name="{{ field.name }}" type="checkbox" value="y"
-      {% if field.data %}
-        checked
-      {% endif %}
-    >
+    {{ checkbox_input(field.id, field.name, field.data) }}
     <label for="{{ field.id }}">
       {{ field.label.text }}
       {% if hint %}
@@ -22,6 +17,22 @@
 {% endmacro %}
 
 
+{% macro checkbox_input(id, name, data=None, value="y") %}
+  <input
+    id="{{ id }}" name="{{ name }}" type="checkbox" value="{{ value }}"
+    {% if data %}
+      checked
+    {% endif %}
+  >
+{% endmacro %}
+
+{% macro unlabelled_checkbox(id, name, data=None, value="y") %}
+  <div class="multiple-choice">
+    {{ checkbox_input(id, name, data, value) }}
+    <label></label>
+  </div>
+{% endmacro %}
+
 {% macro checkbox_group(
   legend,
   fields