Add new MCP tools: get_market_cap, get_insider_news, and search_line_items

[shilok09]

Summary

This PR adds three new MCP tools to the financial-data server to expand its analytical and data retrieval capabilities.

Changes

• get_market_cap()
  Retrieves the market capitalization for a specified company.
• get_insider_news()
  Fetches recent insider-related news articles to provide trading context.
• search_line_items()
  Allows flexible querying of financial line items by keywords or identifiers.

Purpose

These additions enhance the MCP server’s functionality by enabling users to:

• Access market cap data easily
• Monitor insider activity via relevant news
• Perform targeted searches on financial line items

Testing

• All functions tested locally in the MCP environment.
• Confirmed compatibility with existing tools.
• No breaking changes identified.

Reviewer Guidance

Please focus review on:

1. Input validation in each function.
2. Error handling and response structure.
3. Potential performance considerations in search_line_items().

Additional Notes

• Backwards-compatible with the current server API.
• Open to suggestions for refining filters or formatting of returned data.

Looking forward to your feedback! 😊

[shilok09]

This PR also contributes toward addressing feature requests like Issue #13, where users have requested expanded functionality such as SEC Filings and related endpoints. I plan to continue iterating by adding those functions in future PRs.