core&ui: add contest private files (#1053)

Co-authored-by: panda <panda_dtdyy@outlook.com>

packages/ui-default/templates/contest_edit.html

@@ -228,6 +228,20 @@
     </div>
   </div>
   <div class="medium-3 columns">
+    {% if tdoc %}
+    <div class="section side">
+      <div class="section__header">
+        <h1 class="section__title">{{ _('Files') }}</h1>
+        <div class="section__tools">
+          <button class="primary rounded button" name="upload_file">{{ _('Upload') }}</button>
+        </div>
+      </div>
+      {% set sidebar = true %}
+      {% set files = tdoc.files %}
+      {% set filetype = "public" %}
+      {% include "partials/files.html" %}
+    </div>
+    {% endif %}
     {% include 'components/md_hint.html' %}
   </div>
 </div>