base: implemented language button: - `component.menu` can now be used with a `{% call %}`, allowing extra HTML to be added after in the <nav> element - a language dropdown is shown if more than one translation is available, allowing to change page locale - if javascript is available, only the dropdown is visible, and changing it reload the page with new locale - if javascript is not available, a submit button is display to change the locale

--- a/sat_templates/templates/default/static/styles_noscript.css	Wed Apr 10 21:05:56 2019 +0200
+++ b/sat_templates/templates/default/static/styles_noscript.css	Wed Apr 10 21:05:58 2019 +0200
@@ -27,3 +27,11 @@
     max-height: none;
     opacity: 1;
 }
+
+/*********
+ * Menus *
+ *********/
+
+.menu__language button {
+    display: initial;
+}