community: Add PolygonLastQuote Tool and Toolkit (#15990)

**Description:** 
In this PR, I am adding a `PolygonLastQuote` Tool, which can be used to
get the latest price quote for a given ticker / stock.

Additionally, I've added a Polygon Toolkit, which we can use to
encapsulate future tools that we build for Polygon.

**Twitter handle:** [@virattt](https://twitter.com/virattt)

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

libs/community/tests/unit_tests/agent_toolkits/test_imports.py

@@ -14,6 +14,7 @@ EXPECTED_ALL = [
     "O365Toolkit",
     "OpenAPIToolkit",
     "PlayWrightBrowserToolkit",
+    "PolygonToolkit",
     "PowerBIToolkit",
     "SlackToolkit",
     "SteamToolkit",

libs/community/tests/unit_tests/tools/test_imports.py

@@ -79,6 +79,7 @@ EXPECTED_ALL = [
     "OpenAPISpec",
     "OpenWeatherMapQueryRun",
     "PubmedQueryRun",
+    "PolygonLastQuote",
     "RedditSearchRun",
     "QueryCheckerTool",
     "QueryPowerBITool",

libs/community/tests/unit_tests/tools/test_public_api.py

@@ -81,6 +81,7 @@ _EXPECTED = [
     "OpenAPISpec",
     "OpenWeatherMapQueryRun",
     "PubmedQueryRun",
+    "PolygonLastQuote",
     "RedditSearchRun",
     "QueryCheckerTool",
     "QueryPowerBITool",