Create migration module scaffolding, utility service and Trait

Problem/Motivation

As a developer, I want the acquia_dam_migration_tools submodule scaffolded with its core metadata + services files, a utility service holding the migration constants, and the shared MigrationTrait, so that the module is installable and provides the helper logic shared by the wizard and Drush commands.

Acceptance Criteria:

Scaffold:

• acquia_dam_migration_tools.info.yml — dependencies: [acquia_dam:acquia_dam], core_version_requirement: ^9.5 || ^10 || ^11, package: 'Acquia DAM', configure: acquia_dam_migration_tools.migration_config
• acquia_dam_migration_tools.services.yml — acquia_dam_migration_tools.utility registration + logger.channel.acquia_dam_migration_tools

Utility service (AcquiaDamMigrationUtilityService):

• Single source of truth for migration constants: getModuleSettingsName(), getQueueName(), getQueueMapTable(), getLockName(), getAltTextField(), getVocabFieldTypes(), getStateQueueKey() / getStateProgressKey() / getStateProcessFinishedKey() / getStateMigratedDataKey() / getStateFailedUploadsKey(), getResetStateKeys()
• processStoredValues() — re-indexes stored values by media type

Migration trait (MigrationTrait):

• Shared helpers for wizard + Drush: getCoreMediaTypes(), getMigrationConfig(), getDrupalMetadataFieldOptions(), isImageSource(), normalizeMetadataMapping(), source-plugin-ID resolution (getSourcePluginIdFromBundle), sync-method resolution (getSyncMethodFromBundle), DAM media type options (getAcquiaDamMediaTypesAsOptions)
• Lazy getters for injected services (entity type manager, config factory, logger, database, state, media source plugin manager, MediaTypeFieldOptions, utility service)

Tests:

• AcquiaDamMigrationUtilityServiceTest (unit) — constants resolution, media-type filtering, stored-value re-indexing
• MigrationTraitTest (unit) — processStoredValues; core/DAM file-extension resolution; DAM media type options; source-plugin-ID resolution; sync-method resolution