EC-DSA Composite ML-DSA for net8+

[PranavSenthilnathan]

.NETFramework requires more refactoring so I'm planning on doing it in a separate PR

Contributes to #116998

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[Copilot]

Pull Request Overview

This PR implements EC-DSA (Elliptic Curve Digital Signature Algorithm) support for Composite ML-DSA algorithms on .NET 8+. The implementation adds EC-DSA as a second component alongside ML-DSA for quantum-resistant cryptographic schemes.

• Adds a new CompositeMLDsaManaged.ECDsa.cs file implementing the EC-DSA component for Composite ML-DSA
• Updates algorithm metadata to include specific curve and hash algorithm parameters for EC-DSA variants
• Enhances test coverage with additional validation scenarios and cross-algorithm tests

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
System.Security.Cryptography.csproj	Adds the new ECDsa component file to the build
Microsoft.Bcl.Cryptography.csproj	Adds the new ECDsa component file to the BCL package
CompositeMLDsaTestsBase.cs	Updates test methods to properly handle variable signature sizes and adds missing test scenarios
CompositeMLDsaTestHelpers.cs	Adds SEC curve distinction and improves algorithm parameter handling
CompositeMLDsaFactoryTests.cs	Adds comprehensive tests for ECDsa key import validation and cross-algorithm error scenarios
CompositeMLDsaManaged.cs	Updates algorithm metadata with specific ECDsa parameters and removes placeholder implementation
CompositeMLDsaManaged.RSA.cs	Adds key size validation for RSA component imports
CompositeMLDsaManaged.ECDsa.cs	New file implementing full ECDsa component with key generation, import/export, and signing/verification