Document index can be sorted by title

The main document index (and also the children/siblings of a page) can now be filtered and sorted by title. In previous versions this was not the case, because filtering and searching happens on the values stored in the database, which can be different from the displayed title.

While this obstacle has not been overcome now pages which have a displayed title which is different from the title stored in the database are now marked with the symbol "¹". If these pages are found in the result set, a note is displayed explaining why filtering and sorting might not work as expected for these pages.