Support for overriding global MSBuild properties before a project is loaded

[tintoy]

Add an extension-level configuration option msbuildProjectTools.msbuild.globalProperties (type: object) used to configure overrides of the default MSBuild properties used before a project is loaded.

Note that, by design, this option is selectively overridden by more-specific property overrides (such as msbuildProjectTools.msbuild.extensionsPath and msbuildProjectTools.msbuild.extensionsPath32).

Related:

• Feature Request: Parse Directory.Build(.props|.targets) when found in workspace tree #164
• Feature Request: Use regular MSBuild Binary Location #35

[tintoy]

@DoctorKrolic - this seems simple enough to implement; do you see any issues with my proposed solution?