Probabilistic Generic Model and Gaussian Naive Bayes Model

[Alysson-Alves23]

• Added abstract class for probabilistic machine learning models.
• Implemented Gaussian model class assuming data follows a normal distribution.
• Gaussian model includes methods for calculating mean, variance, and probability density function (PDF).
• Supports parameter estimation from data for predictive tasks.
• Added Gaussian Naive Bayes class for classification tasks with continuous features.