cookiebanner: rename DetectedTracker.InsertIfNotExists to Upsert

The method uses ON CONFLICT ... DO UPDATE, so the name now
matches the actual behaviour. TrackerPattern.InsertIfNotExists
keeps its name because it uses ON CONFLICT ... DO NOTHING.

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/coredata/detected_tracker.go

@@ -44,7 +44,7 @@ type (
 	DetectedTrackers []*DetectedTracker
 )
 
-func (dt *DetectedTracker) InsertIfNotExists(
+func (dt *DetectedTracker) Upsert(
 	ctx context.Context,
 	tx pg.Tx,
 	scope Scoper,
@@ -109,7 +109,7 @@ ON CONFLICT (cookie_banner_id, tracker_type, identifier) DO UPDATE
 
 	result, err := tx.Exec(ctx, q, args)
 	if err != nil {
-		return false, fmt.Errorf("cannot insert detected tracker: %w", err)
+		return false, fmt.Errorf("cannot upsert detected tracker: %w", err)
 	}
 
 	return result.RowsAffected() > 0, nil