feat(jobs): add MsBuildProperty for escaped MSBuild properties

[fuguiKz]

Fixes #2719.

What

• Add opt-in MSBuild special character escaping via new MsBuildArgument(value, escapeSpecialCharacters: true).
• Add MsBuildProperty : MsBuildArgument for /p:name=value (joins multiple values with ; and escapes automatically).
• Keep reports readable by showing the unescaped value via ToString() when escaping is enabled.
• Add unit + integration coverage for semicolon-separated values.
• Docs: troubleshooting guide now mentions MsBuildProperty.

Why

MSBuild treats ; as a property separator in /p: so values like DefineConstants=TEST1;TEST2 must be escaped (eg %3B) to work reliably.

Verification

• dotnet test tests/BenchmarkDotNet.Tests/BenchmarkDotNet.Tests.csproj -c Release -f net8.0 --filter FullyQualifiedName~MsBuildArgumentTests
• dotnet test tests/BenchmarkDotNet.IntegrationTests.ManualRunning/BenchmarkDotNet.IntegrationTests.ManualRunning.csproj -c Release -f net8.0 --filter FullyQualifiedName~MsBuildArgumentTests

Context

This follows the combined direction discussed in #2730 / #2732 (opt-in escaping + a dedicated property type).

[timcassell]

Thanks @fuguiKz