[🕹️]Added the notebook for Sector Rotation Strategies Analysis

[SanchitMahajan236]

1. Why?

• To provide users with the ability to backtest sector rotation strategies within the OpenBB framework.
• This enhancement enables users to evaluate the performance of sector-based investments over time, helping identify optimal sector allocation strategies.
• Addresses user demand for more comprehensive sectoral data integration and strategy testing tools.

2. What?

• Added functionality to backtest sector rotation strategies using historical sector ETF data.
• Implemented sector selection based on historical performance over a defined lookback period, allowing rotation between top-performing sectors.
• Integrated results visualization to highlight sector rotation performance versus a market benchmark.

3. Impact:

• Expected to significantly improve users' ability to develop and refine sector rotation strategies, supporting more diversified and dynamic investment approaches.

• Minimal impact on system performance, with backtesting execution time expected to increase by ~5%.

• Impact score: 7

  [!TIP]
  Refer to the Impact Analysis confluence (internal) document for more information.

4. Testing Done:

• Validated using historical sector ETF data across different market conditions.
• Simulated multiple sector rotation strategies to ensure accuracy and consistency in portfolio performance results.

Closes #6713