Add missing button roles for the language chooser and keyboard shortcut menu items

client/src/app/menu/menu.component.html

@@ -104,11 +104,11 @@
 
     <div class="footer d-flex justify-content-between">
       <span class="language">
-        <span tabindex="0" (keyup.enter)="openLanguageChooser()" (click)="openLanguageChooser()" i18n-title title="Change the language" class="icon icon-language"></span>
+        <span tabindex="0" role="button" (keyup.enter)="openLanguageChooser()" (click)="openLanguageChooser()" i18n-title title="Change the language" class="icon icon-language"></span>
       </span>
 
       <span class="shortcuts">
-        <span tabindex="0" (keyup.enter)="openHotkeysCheatSheet()" (click)="openHotkeysCheatSheet()" i18n-title title="Show keyboard shortcuts" class="icon icon-shortcuts"></span>
+        <span tabindex="0" role="button" (keyup.enter)="openHotkeysCheatSheet()" (click)="openHotkeysCheatSheet()" i18n-title title="Show keyboard shortcuts" class="icon icon-shortcuts"></span>
       </span>
     </div>
   </menu>