289 include unrealized gains in backtesting result

[MDUYN]

Pull Request Title: include unrealized gains in backtesting result and add trade db support

Description

This pull request introduces two key features to enhance the backtesting framework:

Include Unrealized Gains in Backtesting Results:

• Unrealized gains are now accounted for in the backtesting metrics.
• Updated calculations ensure a more accurate representation of portfolio performance during backtests.
• Adjusted output to include unrealized gains in performance summaries and reporting.

Trade Database (DB) Support:

• Added support for persisting trades into a database for enhanced record-keeping and post-analysis.
• ntegrated database schema and migration scripts for storing trade data (e.g., entry/exit prices, timestamps, position size).

Fixes #[issue-number] (if applicable).

Type of Change

• Bugfix
• [x ] New feature
• Documentation update
• Refactor/optimization

Checklist

• Code is formatted with black or a similar linter.
• Tests have been added or updated.
• Documentation has been updated (if needed).