replace controller logic with dedicated handler and service classes (CQRS-Lite)

[solverat]

Extracts all business logic from admin controllers into dedicated handler, service, and enricher classes.
Controllers are now thin dispatch layers: they receive a typed Payload, pass it to a Handler, and return the result. Request parsing no longer happens inside controllers or handlers.

Changes 🤯

Handlers & Payloads

Every controller action now has a corresponding Handler (invokable) and a Payload implementing ExtJsPayloadInterface.
The payload is resolved from the request by a new ExtJsValueResolver, keeping Request out of handlers entirely.

Common payload shapes (IdQueryPayload, IdBodyPayload, EmptyPayload, etc.) live in src/Payload/Common/.

File uploads (add-asset, add-asset-compatibility, upload-custom-logo, replace-asset) are covered too, multipart and base64 alike.

Services

Business logic shared across handlers was extracted into service classes under src/Service/:

• Document/DocumentPayloadMapper, DocumentPersistenceCoordinator
• Asset/AssetPayloadMapper, AssetUploadService
• DataObject/DataObjectPayloadMapper
• Grid/GridColumnConfigService, GridBatchService, GridExportService
• Element/EditLockService, Element/SessionService
• Login/LoginPageService
• Portal/DashboardService
• Admin/AdminSettingsService, AdminStatisticsService
• Notification/NotificationFilterParser
• Workflow/WorkflowElementResolver
• Translation/AdminSearchTermResolver

Repository

Persistence-only classes under src/Repository/:

• DashboardRepository

Enrichers

Post-processing of element data was split into enrichers under src/Enricher/:

• Element/AdminStyleEnricher, Element/UserNamesEnricher
• Document/DocumentMetaEnricher, DraftEnricher, PropertiesEnricher, TranslationEnricher
• DataObject/DraftEnricher, CustomLayoutEnricher

Permissions

Access control moved from manual checkPermission() calls inside controller methods to #[IsGranted] attributes on actions, backed by PermissionVoter.

HTTP layer

• ExtJsValueResolver resolves Payload objects from the request via fromRequest()
• ApiResponse DTO for consistent JSON response shape
• AdminExceptionListener centralizes exception-to-response mapping, including ElementLockedException (editlock dialog) and AdminOperationFailedException (recoverable business-rule failures), instead of per-controller try/catch

ExtJS xaction dispatching

ExtJS CRUD endpoints that send a single URL with an xaction parameter (create, update, destroy) are now handled via $this->forward() to dedicated per-action methods.
Each target action has its own typed Payload, Handler, and #[IsGranted] attribute instead of a branching switch statement inside one fat action.

Removed

• src/Controller/Traits/ApplySchedulerDataTrait, UserNameTrait
• src/EventListener/Traits/ControllerTypeTrait