feat(bank-accounts): add transaction retrieval and update service logic

- Implemented a new endpoint to fetch transactions for a specific bank account.
- Refactored the bank account service to streamline transaction handling and balance calculations.
- Removed the bank account balance table and adjusted related logic in workflows and services.
- Enhanced transaction mapping to include references to sales and purchase records.

prisma/migrations/20260105090450_init/migration.sql

@@ -0,0 +1,11 @@
+/*
+  Warnings:
+
+  - You are about to drop the `Bank_Account_Balance` table. If the table is not empty, all the data it contains will be lost.
+
+*/
+-- DropForeignKey
+ALTER TABLE `Bank_Account_Balance` DROP FOREIGN KEY `Bank_Account_Balance_bankAccountId_fkey`;
+
+-- DropTable
+DROP TABLE `Bank_Account_Balance`;