Refactor billing code and add error monitoring

Refactored the code that retrieves the billing customer id by renaming the function getBillingCustomerId to getCustomerId. Also, bolstered error handling: implemented exception capture in particular scenarios across multiple files. If an error occurs, it's now captured and reported to the configured provider.

packages/next/src/utils/index.ts

@@ -12,3 +12,14 @@ export const zodParseFactory =
       throw new Error(`Invalid data: ${err as string}`);
     }
   };
+
+export async function captureException(exception: unknown) {
+  const { getServerMonitoringService } = await import('@kit/monitoring/server');
+
+  const service = await getServerMonitoringService();
+
+  const error =
+    exception instanceof Error ? exception : new Error(exception as string);
+
+  return service.captureException(error);
+}