Bugfix: Prevent rendering of old/wrong set of resources in search list

When entering the search, it displayed the resources from the file list for a short moment,
this has now been fixed and the search always shows the loading spinner first.

After all results have been loaded from the server, the spinner disappears and the result is rendered.

https://github.com/owncloud/web/pull/9881
https://github.com/owncloud/web/issues/9790
