fix: improve data vendor implementations and tool signatures

- Add get_global_news for Alpha Vantage
- Fix get_insider_transactions signature (remove unused curr_date param)
- Remove unnecessary default params from API calls (sort, limit, tab)

tradingagents/agents/analysts/fundamentals_analyst.py

@@ -1,7 +1,7 @@
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
 import time
 import json
-from tradingagents.agents.utils.agent_utils import get_fundamentals, get_balance_sheet, get_cashflow, get_income_statement, get_insider_sentiment, get_insider_transactions
+from tradingagents.agents.utils.agent_utils import get_fundamentals, get_balance_sheet, get_cashflow, get_income_statement, get_insider_transactions
 from tradingagents.dataflows.config import get_config