[ext-fintraffic] Add FintrafficParking extension with persisted paymentMethods

[teppope]

Summary

This is the first increment of the Fintraffic parking extension, focused on paymentMethods. Further fields (e.g. vehicleEntrances, availability conditions) will follow in subsequent PRs once the underlying data model and import pipeline are in place.

Implements the Fintraffic parking extension on top of the feat/parking-extension-hooks infrastructure (#421).

• FintrafficParking — JPA subclass of Parking with a paymentMethods column (stored as a PostgreSQL array via Hibernate's @JdbcTypeCode(SqlTypes.ARRAY)). A Flyway migration (V3__FintrafficParkingExtensions) adds the backing column.
• FintrafficParkingEntityFactory — @Primary factory that instantiates FintrafficParking and registers FintrafficParking.class with Orika. paymentMethods is kept in the exclusion list; enum conversion is handled by the contributor instead.
• FintrafficParkingMapperContributor — translates paymentMethods between org.rutebanken.netex.model.PaymentMethodEnumeration and org.rutebanken.tiamat.model.PaymentMethodEnumeration in both import and export directions. Unknown enum values are silently skipped.
• FintrafficMergingParkingImporter — extends the mergeExtendedFields hook to persist paymentMethods from the incoming entity onto the existing DB entity.
• FintrafficParkingGraphQLTypeContributor — adds paymentMethods as a [PaymentMethodsEnumeration] field to both the parking output and input GraphQL types, including enum type registration.
• FintrafficParkingUpdater — extends the mutation hook to copy paymentMethods from the GraphQL input onto the Tiamat entity before save.

All components are activated by the fintraffic Spring profile.

Type of change

• New feature (non-breaking change which adds functionality)

Dependencies

Depends on #421 — that branch must be merged first (or this PR rebased onto master after that merge).

Tests

• FintrafficParkingIntegrationTest — NeTEx import round-trip: verifies paymentMethods survives import and is present on the persisted entity.
• FintrafficGraphQLParkingIntegrationTest — GraphQL mutation and query: verifies paymentMethods can be set via mutation and read back via parking(id: "...").
• FintrafficParkingMapperContributorTest — unit tests for enum conversion in both directions, including unknown value handling.
• FintrafficMergingParkingImporterTest — verifies merge behaviour: values copied from incoming to existing entity.
• FintrafficParkingEntityFactoryTest — verifies correct class, exclusion list, and instance type.

Follow-up fix (added after initial review)

Added FintrafficEntityScanConfig — an ext-only, @Profile("fintraffic")-guarded
@Configuration that registers org.rutebanken.tiamat.ext.fintraffic.model for JPA
entity scanning via Spring's additive EntityScanPackages.register(). TiamatApplication's
@EntityScan(basePackageClasses = {StopPlace.class, ...}) only covers
org.rutebanken.tiamat.model, so without this, Hibernate never registered
FintrafficParking as an entity and every mutateParking/parking GraphQL operation
failed under the fintraffic profile with "... is not an entity". This does not modify
TiamatApplication.java — the registration is purely additive.

This fix has also been merged forward into every dependent branch in the stack
(feat/ext-fintraffic-info-links, feat/ext-fintraffic-vehicle-entrances,
feat/ext-fintraffic-parking-lighting, feat/ext-fintraffic-parking-opening-hours)
so their PRs remain buildable/testable independently of merge order.

Follow-up fix: Parking never appears in the Read API cache

ReadApiNetexMarshallingService.createEntityRecord derived the Read API cache table's
type column via entity.getClass().getSimpleName(). Under the fintraffic profile,
every Parking is actually persisted/loaded as a FintrafficParking instance (this
branch's subclass), so the column got "FintrafficParking" instead of "Parking" —
never matching the repository's type IN (...) query filter. The row was written
successfully (no exception), but was permanently invisible to every Read API query.

Fixed by adding an entityTypeName(EntityInVersionStructure) helper that maps the known
Tiamat model supertypes (StopPlace, Parking, TopographicPlace, FareZone) to their
NeTEx element type name via instanceof checks, instead of relying on the runtime class
name. Verified end-to-end with a new ReadApiParkingIncrementalSyncIntegrationTest that
activates the real fintraffic-read-api Spring profile (not mocked) and asserts the new
Parking is both written with type='Parking' and returned by the real
streamStopPlaces query used by the Read API.