ci(node): run examples in CI (#1796)

This is done as setup for a PR that will fix the OpenAI dependency
issue.

 * [x] FTS examples
 * [x] Setup mock openai
 * [x] Ran `npm audit fix`
 * [x] sentences embeddings test
 * [x] Double check formatting of docs examples

nodejs/examples/util.ts

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright The LanceDB Authors
+import * as fs from "fs";
+import { tmpdir } from "os";
+import * as path from "path";
+
+export async function withTempDirectory(
+  fn: (tempDir: string) => Promise<void>,
+) {
+  const tmpDirPath = fs.mkdtempSync(path.join(tmpdir(), "temp-dir-"));
+  try {
+    await fn(tmpDirPath);
+  } finally {
+    fs.rmSync(tmpDirPath, { recursive: true });
+  }
+}