perf(import): optimize search for domains claimed by other organizations (#8200)

# Which Problems Are Solved

Improve the performance of human imports by optimizing the query that
finds domains claimed by other organizations.

# How the Problems Are Solved

Use the fields search table introduced in
https://github.com/zitadel/zitadel/pull/8191 by storing each
organization domain as Object ID and the verified status as field value.

# Additional Changes

- Feature flag for this optimization

# Additional Context

- Performance improvements for import are evaluated and acted upon
internally at the moment

---------

Co-authored-by: adlerhurst <silvan.reusser@gmail.com>

cmd/setup/setup.go

@@ -158,6 +158,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 	steps.s27IDPTemplate6SAMLNameIDFormat = &IDPTemplate6SAMLNameIDFormat{dbClient: esPusherDBClient}
 	steps.s28AddFieldTable = &AddFieldTable{dbClient: esPusherDBClient}
 	steps.s29FillFieldsForProjectGrant = &FillFieldsForProjectGrant{eventstore: eventstoreClient}
+	steps.s30FillFieldsForOrgDomainVerified = &FillFieldsForOrgDomainVerified{eventstore: eventstoreClient}
 
 	err = projection.Create(ctx, projectionDBClient, eventstoreClient, config.Projections, nil, nil, nil)
 	logging.OnError(err).Fatal("unable to start projections")
@@ -198,6 +199,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 		steps.s24AddActorToAuthTokens,
 		steps.s26AuthUsers3,
 		steps.s29FillFieldsForProjectGrant,
+		steps.s30FillFieldsForOrgDomainVerified,
 	} {
 		mustExecuteMigration(ctx, eventstoreClient, step, "migration failed")
 	}