Add coredata batch loaders for tracker third parties

Surface the third-party links carried by tracker patterns (org-scoped
ThirdParty via third_party_id, or global CommonThirdParty via
common_tracker_pattern_id) requires three new batch loaders and two
filter dimensions, all kept inside their owning entity tables to honour
the no-cross-entity-JOIN rule.

  * CommonTrackerPatterns gains LoadByIDs and the ID-only
    LoadIDsByCommonThirdPartyID helper, which lets callers translate a
    common third party into a set of common_tracker_pattern_id values
    without ever JOINing against tracker_patterns.

  * CommonThirdParties gains LoadByIDs.

  * TrackerPatterns gains LoadDistinctThirdPartyIDsByCookieBannerID and
    LoadDistinctCommonTrackerPatternIDsByCookieBannerID, used by the
    upcoming CookieBanner.linkedThirdParties resolver to enumerate the
    third parties referenced in a banner.

  * TrackerPatternFilter gains thirdPartyID and commonTrackerPatternIDs
    filter dimensions; the GraphQL layer will dispatch a single
    thirdPartyId argument to the right one based on the GID entity-type
    prefix.

Service-layer wrappers (cookiebanner.GetCommonTrackerPatternsByIDs,
cookiebanner.LoadCommonTrackerPatternIDsByCommonThirdPartyID,
cookiebanner.LoadDistinctThirdPartyIDsByCookieBannerID,
cookiebanner.LoadDistinctCommonTrackerPatternIDsByCookieBannerID, and
thirdparty.GetCommonThirdPartiesByIDs) expose the new loaders to the
console resolvers and dataloaders that follow.

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

pkg/thirdparty/service.go

@@ -50,6 +50,29 @@ func (s *Service) GenerateLogoURL(
 	return &url, nil
 }
 
+func (s *Service) GetCommonThirdPartiesByIDs(
+	ctx context.Context,
+	ids ...gid.GID,
+) (coredata.CommonThirdParties, error) {
+	var parties coredata.CommonThirdParties
+
+	err := s.pg.WithConn(
+		ctx,
+		func(ctx context.Context, conn pg.Querier) error {
+			if err := parties.LoadByIDs(ctx, conn, ids); err != nil {
+				return fmt.Errorf("cannot load common third parties by ids: %w", err)
+			}
+
+			return nil
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return parties, nil
+}
+
 func (s *Service) Search(ctx context.Context, name string) ([]*coredata.CommonThirdParty, error) {
 	var parties coredata.CommonThirdParties