Forward Home and End keys to the editor when completing

It's annoying and not very useful if they get grabbed and handled by the
completion list. This happened as a side effect of
fc1780f1.

src/plugins/texteditor/completionwidget.cpp

@@ -368,6 +368,9 @@ bool CompletionListView::event(QEvent *e)
 
         case Qt::Key_Right:
         case Qt::Key_Left:
+        case Qt::Key_Home:
+        case Qt::Key_End:
+            // We want these navigation keys to work in the editor, so forward them
             break;
 
         case Qt::Key_Tab: