Search is now handled by TrackListActivity and MarkerListActivity.

* data is loaded via cursor,
* removed custom ranking (handled in database),
* search text is wrapped with wildcards, and
* search view can be closed by back button.

Fixes #492.

src/main/java/de/dennisguse/opentracks/io/file/exporter/ExportActivity.java

@@ -24,7 +24,6 @@ import android.view.View;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
-import androidx.appcompat.widget.Toolbar;
 import androidx.core.content.ContextCompat;
 import androidx.documentfile.provider.DocumentFile;
 import androidx.fragment.app.FragmentActivity;