Introduces SeleniumURLLoader for JavaScript-Dependent Web Page Data Retrieval (#2291)

### Summary
This PR introduces a `SeleniumURLLoader` which, similar to
`UnstructuredURLLoader`, loads data from URLs. However, it utilizes
`selenium` to fetch page content, enabling it to work with
JavaScript-rendered pages. The `unstructured` library is also employed
for loading the HTML content.

### Testing
```bash
pip install selenium
pip install unstructured
```

```python
from langchain.document_loaders import SeleniumURLLoader

urls = [
    "https://www.youtube.com/watch?v=dQw4w9WgXcQ",
    "https://goo.gl/maps/NDSHwePEyaHMFGwh8"
]

loader = SeleniumURLLoader(urls=urls)
data = loader.load()
```

docs/modules/indexes/document_loaders/examples/url.ipynb

@@ -52,6 +52,66 @@
    "source": [
     "data = loader.load()"
    ]
+  },
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "id": "f3afa135",
+   "metadata": {},
+   "source": [
+    "# Selenium URL Loader\n",
+    "\n",
+    "This covers how to load HTML documents from a list of URLs using the `SeleniumURLLoader`.\n",
+    "\n",
+    "Using selenium allows us to load pages that require JavaScript to render.\n",
+    "\n",
+    "## Setup\n",
+    "\n",
+    "To use the `SeleniumURLLoader`, you will need to install `selenium` and `unstructured`.\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "5fc50835",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from langchain.document_loaders import SeleniumURLLoader"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "24e896ce",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "urls = [\n",
+    "    \"https://www.youtube.com/watch?v=dQw4w9WgXcQ\",\n",
+    "    \"https://goo.gl/maps/NDSHwePEyaHMFGwh8\"\n",
+    "]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "60a29397",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "loader = SeleniumURLLoader(urls=urls)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "0090cd57",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "data = loader.load()"
+   ]
   }
  ],
  "metadata": {