Toggle week_view filters

(cherry picked from commit 7aa0d336)

aleksis/apps/alsijil/static/css/alsijil/week_view.css

+@media screen and (max-width: 600px) {
+    #toggle-row button[type=submit] {
+        width: 100%;
+        margin-bottom: 1em;
+    }
+}
+
 .horizontal-scroll-container {
     overflow-x: scroll;
     display: flex;

aleksis/apps/alsijil/templates/alsijil/class_register/week_view.html

@@ -45,15 +45,23 @@
   {{ week_select|json_script:"week_select" }}
   <script type="text/javascript" src="{% static "js/chronos/week_select.js" %}"></script>
   <div class="row">
-    <div class="col s12">
+    <div id="toggle-row" class="col s12 m8 l10 {% if lesson_periods %}pre-hidden{% endif %}">
       <form method="post" action="">
         {% csrf_token %}
         {% form form=select_form %}{% endform %}
-        <button type="submit" class="btn waves-effect waves-light">
+        <button type="submit" class="btn waves-effect waves-light primary-color">
+          <i class="material-icons left">check</i>
           {% blocktrans %}Select{% endblocktrans %}
         </button>
       </form>
     </div>
+    <div class="col s12 m4 l2 right">
+      <button type="button" class="btn waves-effect waves-light hundred-percent" id="toggle-button">
+        <i class="material-icons left">
+          filter_alt
+        </i> {% trans "Toggle filters" %}
+      </button>
+    </div>
   </div>
 
 
@@ -439,7 +447,12 @@
           $("#id_teacher").change(function () {
               $("#id_group").val("").formSelect();
           });
+          $("#toggle-row.pre-hidden").hide();
+
       });
+      $("#toggle-button").click(function () {
+          $("#toggle-row").toggle();
+      })
       $(".unfold-trigger").click(function (event) {
           console.log(event);
           let target = event.target;