Fix wrong inbox notification counters — radicle-desktop

Avoid counting grouped notifications separately and omit notifications for deleted objects.

         notification::ListNotificationsError,
     > {
         let stmt = self.db.prepare(
             "SELECT ref, repo, COUNT(*) as count
             "SELECT COUNT(DISTINCT substr(ref, 66)) count, ref, repo
                  FROM `repository-notifications`
                  WHERE ref LIKE '%cobs%'
                  WHERE new NOT NULL AND (ref LIKE '%cobs/xyz.radicle.patch%' OR ref LIKE '%cobs/xyz.radicle.issue%')
                  GROUP BY repo",
         )?;