Add namespace and type mapping capabilities

[jbrinkman]

This PR implements task 4.2 "Add namespace and type mapping capabilities" from the dotnet-api-diff spec.

Changes

• Created the INameMapper interface for mapping namespaces and type names
• Implemented the NameMapper class with support for:
  • One-to-many namespace mappings
  • Type name mappings
  • Auto-mapping of types with the same name but different namespaces
  • Case-sensitive or case-insensitive mapping options
• Updated the ApiComparer class to use the NameMapper
• Added comprehensive unit tests for the NameMapper
• Added integration tests for the ApiComparer with NameMapper
• Updated the Program.cs file to register the NameMapper in the DI container

Testing

All tests are passing, including the existing tests that were updated to include the NameMapper parameter.

Closes #4.2

[Copilot]

Pull Request Overview

This PR implements comprehensive namespace and type mapping capabilities for the dotnet-api-diff tool, enabling comparison of types across renamed namespaces and different organizational structures.

• Adds INameMapper interface and NameMapper implementation supporting one-to-many mappings and auto-mapping
• Integrates name mapping logic into ApiComparer to handle namespace transformations during comparisons
• Updates dependency injection configuration to register the NameMapper service

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/DotNetApiDiff.Tests/ApiExtraction/NameMapperTests.cs	Comprehensive unit tests for NameMapper functionality
tests/DotNetApiDiff.Tests/ApiExtraction/ApiComparerWithMappingTests.cs	Integration tests for ApiComparer with mapping capabilities
tests/DotNetApiDiff.Tests/ApiExtraction/ApiComparerTests.cs	Updated constructor to include INameMapper dependency
tests/DotNetApiDiff.Tests/ApiExtraction/ApiComparerManualTests.cs	Added mock NameMapper to manual test setup
src/DotNetApiDiff/Program.cs	Registered NameMapper in dependency injection container
src/DotNetApiDiff/Interfaces/INameMapper.cs	Interface definition for namespace and type mapping operations
src/DotNetApiDiff/ApiExtraction/NameMapper.cs	Core implementation of mapping logic with configuration support
src/DotNetApiDiff/ApiExtraction/ApiComparer.cs	Integrated name mapping into type comparison workflow
.kiro/specs/dotnet-api-diff/tasks.md	Updated task completion status

[jbrinkman]

I've addressed both code review comments:

1. In NameMapper.cs, I extracted the string concatenation logic into a helper method CombineNamespaceParts and updated both places where it was used (in MapNamespace and MapFullTypeName methods).

2. In ApiComparer.cs, I extracted the auto-mapping logic for finding types by simple name into a private helper method TryFindTypeBySimpleName and updated both places where it was used.

These changes improve code readability and reduce duplication while maintaining the same functionality.

[jbrinkman]

I've addressed all the code review comments by extracting helper methods to reduce code duplication. The changes maintain the same functionality while improving code readability and maintainability.