Include full command line in MTP validation errors

[Copilot]

Bug Fix

Invalid MTP command-line errors only reported the failing option, which is insufficient when the invoked command is hidden by test infrastructure or CI logs.

• Command context

  • Preserve the original parsed command line in CommandLineParseResult.
  • Append it to relevant validation failures.

• Validation coverage

  • Applies to parser errors, unknown options, invalid arity, and invalid option arguments.
  • Adds targeted coverage for --dotnet-test-pipe arity failures with a test DLL/tool name.

Example output:

Option '--dotnet-test-pipe' from provider 'Platform command line provider' (UID: PlatformCommandLineProvider) expects at most 1 arguments
Command line: TestProject.dll --dotnet-test-pipe pipe extra

[Copilot]

Pull request overview

Augments MTP command-line validation errors to include the full original command line, making failures easier to diagnose when the invocation is hidden by surrounding test/CI infrastructure.

Changes:

• CommandLineParseResult now carries the original argv joined as a CommandLine string, populated by Parser from a snapshot taken before parsing mutates the argument list.
• CommandLineOptionsValidator appends a localized Command line: {0} line (new CommandLineValidationCommandLine resource) to parser errors, unknown-option errors, arity errors, and option-argument validation errors.
• Tests updated for the new error format and a new --dotnet-test-pipe arity-failure test exercises the tool-name + extra-argument case; resx + xlf resources updated across all locales.

Show a summary per file

File	Description
src/Platform/Microsoft.Testing.Platform/CommandLine/ParseResult.cs	Replaces primary constructor with explicit constructors; adds internal CommandLine property storing the joined original args.
src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs	Snapshots args before parsing and forwards them to the new internal constructor.
src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineOptionsValidator.cs	Wraps invalid validation results with the new Command line: suffix via AddCommandLine/InvalidWithCommandLine helpers.
src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx	Adds CommandLineValidationCommandLine resource string.
src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.*.xlf	Generated new-state translation entries for the new resource across all locales.
test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs	Updates expected error strings and adds tool-name + arity test.
test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/ArgumentArityTests.cs	Updates expected error strings to include the appended command line.

Copilot's findings

• Files reviewed: 19/19 changed files
• Comments generated: 0

[Evangelink]

@copilot let's use real content and not wildcard here.

[Copilot]

Addressed in 1337c8a by asserting the exact command line instead of using a wildcard.