Fix: logger service injection

[joyet-simon]

Reason for change

Linear task

When BusinessEventsService::onOrderConfirmed() threw a BusinessEventsServiceException, it was propagated as a GatewayServiceException from GatewayService::woocommerceOrderStatusChanged(), blocking the WooCommerce order status change flow.

Code changes

Catch & log instead of throw: GatewayService now catches BusinessEventsServiceException and logs it as a debug message instead of re-throwing it as a GatewayServiceException.
Make LoggerService a required dependency: Removed nullable ?LoggerService with NullLogger fallback across 7 classes. LoggerService is now a required constructor parameter, enforcing proper DI.
Fix missing LoggerService in ConfigFormMapper: Added LoggerService injection to ConfigFormMapper so it can pass it to FeePlanConfiguration (which now requires it).

Fixed FeePlanConfigurationTest, FeePlanProviderTest, ConfigFormMapperTest to pass LoggerService mock.
Created GatewayServiceTest with 3 tests covering the new behavior (exception logged, success case, order not found).

How to test

As a reviewer, you are encouraged to test the PR locally.

Checklist for authors and reviewers

• The title of the PR uses business wording, not technical jargon, for the changelog readers to understand it
• The PR implements the changes asked in the referenced task / issue
• The automated tests are compliant with the testing strategy
• The tests are relevant, and cover the corner/error cases, not only the happy path
• You understand the impact of this PR on existing code/features
• The changes include adequate logging and Datadog traces
• Documentation is updated (API, developer documentation, ADR, Notion...)

Non applicable