Support mutualTLS security scheme type

[mdaneri]

Pull Request

Description

Adds support for the mutualTLS security scheme type by introducing SecuritySchemeType.MutualTLS and ensuring it serializes correctly.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Other (please describe):

Related Issue(s)

Fixes #2693

Changes Made

• Add SecuritySchemeType.MutualTLS (with display name mutualTLS)
• Handle mutualTLS serialization in OpenApiSecurityScheme (no extra fields)
• Add a reader sample + test validating mutualTLS parsing

Testing

• Unit tests added/updated
• Integration tests added/updated
• Manual testing performed
• All existing tests pass

Notes: dotnet build Microsoft.OpenApi.sln.

Checklist

• My code follows the code style of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Versions applicability

• My change applies to the version 1.X of the library, if so PR link:
• My change applies to the version 2.X of the library, if so PR link:
• My change applies to the version 3.X of the library, if so PR link:
• I have evaluated the applicability of my change against the other versions above.

Additional Notes

None.

[baywet]

Thanks for the contribution!

[baywet]

Thank you for making the changes!