Add BinomialTreeModel for Option Pricing by Feature/binomial tree models

[Liberxue]

Add BinomialTreeModel for Option Pricing

Description:

This PR introduces the BinomialTreeModel for option pricing.

The implementation is based on the following references:

Binomial Models by Kent University

Binomial Option Pricing by the University of Leicester

Changes:

• Added BinomialTreeModel struct with steps parameter.
• Implemented the OptionPricingModel trait for BinomialTreeModel.
• Calculated call and put option prices using the binomial tree method.
• Calculated Greeks (Delta, Gamma, Theta, Vega, Rho) for the options.
• Testing:
• Included unit tests for call and put option pricing.
• Added tests for the calculation of Greeks.

Notes:

The model uses a default of 100 steps in the binomial tree, which can be customized.
Calculations are performed using the risk-neutral probability method described in the references.