Filtering by title in the "Children" view is ineffective

Note: this is not about pages with computed titles. E.g. in the Sandbox it does not work, too.

Despite of XWIKI-12929 there is a filter for titles in the "Children" view for every (non-terminal) page. Trying to filter by title does not affect the results, however.

Probably the filter field should be removed until XWIKI-14647 is done.