Add AWS Cost Explorer forecast functionality

[NithinChandranR-AWS]

This PR adds AWS Cost Explorer forecast functionality to the CUDOS Framework, including:

Features Added

• New forecast command in cid-cmd for generating cost forecasts
• Modern QuickSight dashboard with enhanced visualizations
• CloudFormation template for automated deployment
• Terraform module integration
• Enhanced SQL view with advanced analytics fields

Implementation Details

• Added Python command module for forecast generation
• Created dashboard definition with modern aesthetics
• Implemented responsive layouts and interactive elements
• Added support for all Cost Explorer dimensions and metrics
• Included confidence interval visualization and analysis

Testing

The implementation has been tested with:

• Local command execution
• Dashboard deployment via cid-cmd
• CloudFormation template validation

Documentation

Added documentation in docs/cost_forecast.md