[MTP dotnet test]: Allow specifying project, solution, directory, or test modules as positional argument

[Youssef1313]

This brings back the same behavior that was with VSTest, where we don't require --project and similar options for specifying what to test.

To limit the impact of this change, we only consider the first unmatched token.

This helps AI agents that always get confused and call MTP incorrectly.

[Copilot]

Pull request overview

This PR changes the dotnet test command for Microsoft Testing Platform (MTP) to allow specifying projects, solutions, directories, or test modules as positional arguments (without requiring explicit switches like --project, --solution, or --test-modules), matching the behavior that existed in VSTest. The change only considers the first unmatched token to limit impact.

Changes:

• Moved validation logic from ValidationUtility.cs to MSBuildUtility.cs and enhanced it to handle positional arguments
• Added positional argument parsing in GetPositionalArguments() that detects file types and treats the first matching token as a positional argument
• Updated PathOptions record to include TestModules field and renamed UnmatchedTokens to TestApplicationArguments in BuildOptions

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
MSBuildUtility.cs	Added GetPositionalArguments() and ValidatePathOptions() to parse and validate positional arguments for projects, solutions, and test modules
ValidationUtility.cs	Removed ValidateSolutionOrProjectOrDirectoryOrModulesArePassedCorrectly() and simplified ValidateMutuallyExclusiveOptions() to work with parsed path options
Options.cs	Added TestModules field to PathOptions and renamed UnmatchedTokens to TestApplicationArguments in BuildOptions for clarity
MicrosoftTestingPlatformTestCommand.cs	Reordered operations to parse build options before validation and updated condition to check PathOptions.TestModules
TestModulesFilterHandler.cs	Changed method signature to accept testModules string parameter instead of extracting it from ParseResult
TestApplication.cs	Updated to use renamed TestApplicationArguments field instead of UnmatchedTokens