Enhancement: Search improvements

We've improved the search, it will show now if no results according to term was found or if the results exceeds the
search limit.
We've also navigate to the last page while clicking the x  in the search input field.

https://github.com/owncloud/web/pull/7586
https://github.com/owncloud/web/issues/5644
https://github.com/owncloud/web/issues/7587

