feat: implement tax switch functionality with Nama adapter

- Add DTOs for tax switch operations including payloads and results.
- Create SalesInvoiceFiscalSwitchService to handle sending and retrieving tax data.
- Implement SalesInvoiceFiscalService for managing invoice tax submissions and results persistence.
- Develop NamaTaxSwitchAdapter for interfacing with the external tax service.
- Introduce NamaTaxRequestDto and related classes for structured tax requests.

prisma/migrations/20260428082555_add_fiscal_switch_to_partner/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE `partners` ADD COLUMN `fiscal_switch_type` ENUM('NAMA', 'SUN') NOT NULL DEFAULT 'NAMA';