Avoids allowing to query for all tabs easily and also reduces DBus traffic somewhat.

Still finds all my tabs.
Ideally, the filtering is done on the extension side already but that requires more effort and especially a compatibility path, however I don't really consider older extension with newer host a valid usecase since extension is easily installable and updatable through the browser store, whereas host comes from distro and might be old. For now, I'll leave it at that.