Refactor TestMethodInfo.cs into focused partial class files

[Copilot]

TestMethodInfo.cs had grown to 1113 lines, making it hard to navigate. Splits it into focused partial class files using idiomatic C#.

File split

File	Lines	Contents
TestMethodInfo.cs	202	Fields, constructor, properties, InvokeAsync, GetTestMethodAttribute, GetRetryAttribute
TestMethodInfo.ArgumentResolution.cs	85	SetArguments, ResolveArguments
TestMethodInfo.Execution.cs	368	ExecuteInternalAsync, ExecuteInternalWithTimeoutAsync, GetTestTimeout, ThrowMultipleAttributesException, GetRealException, CreateTestClassInstance
TestMethodInfo.ExceptionHandling.cs	92	HandleMethodException
TestMethodInfo.Lifecycle.cs	373	All TestInitialize/TestCleanup fixture invocation methods
TestMethodInfo.TestContext.cs	56	SetTestContext

Notes

• Pure reorganization — no logic changes, no signature changes, no access modifier changes
• Each partial file carries only the using directives it actually needs
• Also fixes a pre-existing typo in a comment: Uwnrap → Unwrap

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• c50vsblobprodcus330.vsblob.vsassets.io
  • Triggering command: /usr/bin/dotnet dotnet restore test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/MSTestAdapter.PlatformServices.UnitTests.csproj --ignore-failed-sources (dns block)
• jd4vsblobprodcus366.vsblob.vsassets.io
  • Triggering command: /usr/bin/dotnet dotnet restore test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/MSTestAdapter.PlatformServices.UnitTests.csproj --ignore-failed-sources (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)