refactor: Use internal namespace for the existing API

packages/backend/test/mocks/rest/internal/api/v1/payment/get-paddle-info.js

@@ -0,0 +1,17 @@
+const getPaddleInfoMock = async () => {
+  return {
+    data: {
+      sandbox: true,
+      vendorId: 'sampleVendorId',
+    },
+    meta: {
+      count: 1,
+      currentPage: null,
+      isArray: false,
+      totalPages: null,
+      type: 'Object',
+    },
+  };
+};
+
+export default getPaddleInfoMock;

packages/backend/test/mocks/rest/internal/api/v1/payment/get-plans.js

@@ -0,0 +1,22 @@
+const getPaymentPlansMock = async () => {
+  return {
+    data: [
+      {
+        limit: '10,000',
+        name: '10k - monthly',
+        price: '€20',
+        productId: '47384',
+        quota: 10000,
+      },
+    ],
+    meta: {
+      count: 1,
+      currentPage: null,
+      isArray: true,
+      totalPages: null,
+      type: 'Object',
+    },
+  };
+};
+
+export default getPaymentPlansMock;