feat: Add Bigquery detect_anomalies tool

This change introduces a new `detect_anomalies` tool in `query_tool.py` which uses BigQuery ML's `CREATE MODEL` with `ARIMA_PLUS` type and `ML.DETECT_ANOMALIES` to detect anomalies. The new function is also added to the `bigquery_toolset`.

PiperOrigin-RevId: 825181489

tests/unittests/tools/bigquery/test_bigquery_toolset.py

@@ -41,7 +41,7 @@ async def test_bigquery_toolset_tools_default():
   tools = await toolset.get_tools()
   assert tools is not None
 
-  assert len(tools) == 8
+  assert len(tools) == 9
   assert all([isinstance(tool, GoogleTool) for tool in tools])
 
   expected_tool_names = set([
@@ -53,6 +53,7 @@ async def test_bigquery_toolset_tools_default():
       "ask_data_insights",
       "forecast",
       "analyze_contribution",
+      "detect_anomalies",
   ])
   actual_tool_names = set([tool.name for tool in tools])
   assert actual_tool_names == expected_tool_names