community: Add PolygonAggregates tool (#18882)

**Description:**
In this PR, I am adding a `PolygonAggregates` tool, which can be used to
get historical stock price data (called aggregates by Polygon) for a
given ticker.

Polygon
[docs](https://polygon.io/docs/stocks/get_v2_aggs_ticker__stocksticker__range__multiplier___timespan___from___to)
for this endpoint.

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

libs/community/langchain_community/tools/polygon/aggregates.py

@@ -0,0 +1,77 @@
+from typing import Optional, Type
+
+from langchain_core.callbacks import CallbackManagerForToolRun
+from langchain_core.pydantic_v1 import BaseModel, Field
+from langchain_core.tools import BaseTool
+
+from langchain_community.utilities.polygon import PolygonAPIWrapper
+
+
+class PolygonAggregatesSchema(BaseModel):
+    """Input for PolygonAggregates."""
+
+    ticker: str = Field(
+        description="The ticker symbol to fetch aggregates for.",
+    )
+    timespan: str = Field(
+        description="The size of the time window. "
+        "Possible values are: "
+        "second, minute, hour, day, week, month, quarter, year. "
+        "Default is 'day'",
+    )
+    timespan_multiplier: int = Field(
+        description="The number of timespans to aggregate. "
+        "For example, if timespan is 'day' and "
+        "timespan_multiplier is 1, the result will be daily bars. "
+        "If timespan is 'day' and timespan_multiplier is 5, "
+        "the result will be weekly bars.  "
+        "Default is 1.",
+    )
+    from_date: str = Field(
+        description="The start of the aggregate time window. "
+        "Either a date with the format YYYY-MM-DD or "
+        "a millisecond timestamp.",
+    )
+    to_date: str = Field(
+        description="The end of the aggregate time window. "
+        "Either a date with the format YYYY-MM-DD or "
+        "a millisecond timestamp.",
+    )
+
+
+class PolygonAggregates(BaseTool):
+    """
+    Tool that gets aggregate bars (stock prices) over a
+    given date range for a given ticker from Polygon.
+    """
+
+    mode: str = "get_aggregates"
+    name: str = "polygon_aggregates"
+    description: str = (
+        "A wrapper around Polygon's Aggregates API. "
+        "This tool is useful for fetching aggregate bars (stock prices) for a ticker. "
+        "Input should be the ticker, date range, timespan, and timespan multiplier"
+        " that you want to get the aggregate bars for."
+    )
+    args_schema: Type[PolygonAggregatesSchema] = PolygonAggregatesSchema
+
+    api_wrapper: PolygonAPIWrapper
+
+    def _run(
+        self,
+        ticker: str,
+        timespan: str,
+        timespan_multiplier: int,
+        from_date: str,
+        to_date: str,
+        run_manager: Optional[CallbackManagerForToolRun] = None,
+    ) -> str:
+        """Use the Polygon API tool."""
+        return self.api_wrapper.run(
+            mode=self.mode,
+            ticker=ticker,
+            timespan=timespan,
+            timespan_multiplier=timespan_multiplier,
+            from_date=from_date,
+            to_date=to_date,
+        )