Add global market state management

[fabian1710]

This PR introduces a global market state management system to handle market data across the application.

Key changes:

1. Added new state.py module with MarketState class
2. Integrated market state in main.py and crew.py
3. Added proper state initialization and updates in the trading crew

The market state tracks:

• Current trading symbol and timeframe
• Current price
• Historical price data
• Technical indicators
• Last update timestamp

The state can be easily accessed from any part of the application by importing the market_state instance from state.py.