feat(medusa): Convert SystemPaymentProvider to TypeScript (#1988)

**What**
- convert system payment provider to typescript

Fixes CORE-397

Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

.changeset/thick-cows-guess.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/medusa": patch
+---
+
+Convert SystemPaymentProvider to TypeScript

packages/medusa/src/services/system-payment-provider.ts

@@ -0,0 +1,55 @@
+import { EntityManager } from "typeorm"
+import { TransactionBaseService } from "../interfaces/transaction-base-service"
+
+class SystemProviderService extends TransactionBaseService {
+  protected manager_: EntityManager
+  protected transactionManager_: EntityManager | undefined
+
+  static identifier = "system"
+
+  constructor(_) {
+    super(_)
+  }
+
+  async createPayment(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async getStatus(_): Promise<string> {
+    return "authorized"
+  }
+
+  async getPaymentData(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async authorizePayment(_): Promise<Record<string, unknown>> {
+    return { data: {}, status: "authorized" }
+  }
+
+  async updatePaymentData(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async updatePayment(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async deletePayment(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async capturePayment(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async refundPayment(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+
+  async cancelPayment(_): Promise<Record<string, unknown>> {
+    return {}
+  }
+}
+
+export default SystemProviderService