feat: Implement get invoices API endpoint

packages/backend/test/mocks/rest/api/v1/users/get-invoices.ee.js

@@ -0,0 +1,14 @@
+const getInvoicesMock = async (invoices) => {
+  return {
+    data: invoices,
+    meta: {
+      count: invoices.length,
+      currentPage: null,
+      isArray: true,
+      totalPages: null,
+      type: 'Object',
+    },
+  };
+};
+
+export default getInvoicesMock;