avatar/update: made "select" button accessible

app/views/avatar/update.php

@@ -26,7 +26,7 @@
                     ) ?>
                 </p>
 
-                <a onclick="javascript:void 0" class=button><?= _('Auswählen') ?></a>
+                <a class="button" tabindex="0"><?= _('Auswählen') ?></a>
             </label>
 
             <input type="hidden" name="cropped-image" id="cropped-image" value="">

resources/assets/javascripts/bootstrap/avatar.js

@@ -43,4 +43,13 @@ STUDIP.domReady(() => {
             });
         });
     }
+
+    //"Redirecting" the event is necessary so that the avatar image upload
+    //is accessible by pressing the enter key when its focused.
+    jQuery(document).on('keydown', 'form.settings-avatar label.file-upload a.button', function(event) {
+        if (event.code == "Enter") {
+            //The enter key has been pressed.
+            jQuery(this).parent('.file-upload').trigger('click');
+        }
+    });
 });