add testWithClientPool and first pool test

packages/client/lib/client/pool.spec.ts

@@ -0,0 +1,11 @@
+import { strict as assert } from 'node:assert';
+import testUtils, { GLOBAL } from '../test-utils';
+
+describe.only('RedisClientPool', () => {
+  testUtils.testWithClientPool('sendCommand', async pool => {
+    assert.equal(
+      await pool.sendCommand(['PING']),
+      'PONG'
+    );
+  }, GLOBAL.SERVERS.OPEN);
+});