Obey tracker ignored files/directories in simple search engine

Trackers allows users to exclude files and directories from the index. By default, tracker excludes directories like "lost+found", "po", and other generated directories. It also excludes some type files, such as "*~", matching the backups created by some applications.

Nautilus does not use these patterns when doing the simple recursive search, which means that users have no way to remove these results that are not useful.

This commit loads the patterns from trackers gsettings and checks them while searching. This is applied when hidden files are not shown.