community: Add PolygonAPIWrapper and get_last_quote endpoint (#15971)

- **Description:** Added a `PolygonAPIWrapper` and an initial
`get_last_quote` endpoint, which allows us to get the last price quote
for a given `ticker`. Once merged, I can add a Polygon tool in `tools/`
for agents to use.
- **Twitter handle:** [@virattt](https://twitter.com/virattt)

The Polygon.io Stocks API provides REST endpoints that let you query the
latest market data from all US stock exchanges.

libs/community/tests/integration_tests/utilities/test_polygon.py

@@ -0,0 +1,9 @@
+"""Integration test for Polygon API Wrapper."""
+from langchain_community.utilities.polygon import PolygonAPIWrapper
+
+
+def test_get_last_quote() -> None:
+    """Test for getting the last quote of a ticker from the Polygon API."""
+    polygon = PolygonAPIWrapper()
+    output = polygon.run("get_last_quote", "AAPL")
+    assert output is not None