Add HTML formatter with configuration section and enhanced UI

[jbrinkman]

🎨 HTML Formatter Enhancement

This PR introduces a comprehensive HTML formatter that significantly improves the user experience for API comparison reports.

✨ Key Features

🔍 Rich HTML Reports

• Professional UI design with modern styling and gradients
• Mobile-responsive layout with proper breakpoints
• Interactive elements for better user experience
• Syntax-highlighted code signatures

⚙️ Configuration Context

• Collapsible configuration section showing all settings that affect comparison results
• Displays filters, mappings, exclusions, and breaking change rules
• Helps users understand why certain results appear in the report
• Proper formatting for complex configuration structures

📁 Enhanced File Output

• New parameter for saving reports to files
• Validation requiring output files for non-console formats
• Separates formatted reports from log output for better usability

🎯 Improved Metadata Layout

• Card-based design for assembly information
• Better handling of long assembly file paths
• Cleaner statistics display with proper visual hierarchy
• Fixed configuration section layout to prevent text wrapping

🎛️ Interactive Elements

• Collapsible signature details for API members
• Toggle buttons for configuration sections
• Smooth transitions and hover effects
• JavaScript-powered interactivity

🔧 Technical Improvements

• Configuration Integration: Updates configuration object with actual command-line options used
• Responsive Design: CSS Grid and Flexbox layouts that work on all screen sizes
• Type Safety: Proper enum conversion for ReportFormat
• Error Handling: Validation for required parameters

📋 Files Changed

• • New comprehensive HTML formatter
• • Added output file parameter and configuration updates
• • Added configuration property
• • Integrated HTML formatter
• • Updated service registration

🧪 Testing

The HTML formatter has been tested with real assembly comparisons and produces professional, readable reports that provide much better context than the previous console-only output.

📖 Usage

# Generate HTML report saved to file
dotnet run -- compare assembly1.dll assembly2.dll --output html --output-file report.html

# Configuration section shows all settings affecting the comparison
# Interactive elements allow drilling down into signature details

This enhancement makes the tool much more user-friendly and provides the necessary context to understand comparison results.