community: Add PolygonFinancials Tool (#18324)

**Description:**
In this PR, I am adding a `PolygonFinancials` tool, which can be used to
get financials data for a given ticker. The financials data is the
fundamental data that is found in income statements, balance sheets, and
cash flow statements of public US companies.

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

libs/community/langchain_community/agent_toolkits/polygon/toolkit.py

@@ -2,7 +2,11 @@ from typing import List
 
 from langchain_community.agent_toolkits.base import BaseToolkit
 from langchain_community.tools import BaseTool
-from langchain_community.tools.polygon import PolygonLastQuote, PolygonTickerNews
+from langchain_community.tools.polygon import (
+    PolygonFinancials,
+    PolygonLastQuote,
+    PolygonTickerNews,
+)
 from langchain_community.utilities.polygon import PolygonAPIWrapper
 
 
@@ -22,6 +26,9 @@ class PolygonToolkit(BaseToolkit):
             PolygonTickerNews(
                 api_wrapper=polygon_api_wrapper,
             ),
+            PolygonFinancials(
+                api_wrapper=polygon_api_wrapper,
+            ),
         ]
         return cls(tools=tools)