feat(frontend+billing): integrate billing UI and navigation into Turnier module

- **Navigation Updates:**
  - Added `AppScreen.Billing` route for participant billing linked to an event and tournament.

- **UI Additions:**
  - Introduced `BillingScreen` and `BillingViewModel` for participant account management and manual transactions.
  - Updated `TurnierAbrechnungTab` to include `BillingScreen` and enable account interaction.

- **Turnier Enhancements:**
  - Enhanced `NennungenTabContent` to support navigation to billing via a new interaction.
  - Added billing feature as a dependency to `turnier-feature`.

- **Billing Domain:**
  - Extended `Money` to include subtraction operation and improved formatting for negative amounts.
  - Added DTOs (`TeilnehmerKontoDto`, `BuchungDto`, `BuchungRequest`) for seamless data exchange with backend.

- **Test Improvements:**
  - Updated `PreviewTurnierAbrechnungTab` to include interactive billing placeholder.

- **Misc Updates:**
  - Enhanced breadcrumb navigation for billing in `DesktopMainLayout` for better user experience.

frontend/features/turnier-feature/build.gradle.kts

@@ -18,6 +18,7 @@ kotlin {
       implementation(projects.frontend.core.domain)
       implementation(projects.frontend.core.network)
       implementation(projects.frontend.core.navigation)
+      implementation(projects.frontend.features.billingFeature)
       implementation(project(":core:zns-parser"))
       implementation(compose.desktop.currentOs)
       implementation(compose.foundation)