Dependency config needs a nugetPackageLang field for nugetPackage objects

[jonthysell]

Summary

Dependency config needs a nugetPackageLang field for nugetPackage objects (and should be verifying all required fields are present)

• nugetPackage object needs to specify every field manually in react-native.config.js that will be needed by autolinking
  • packageName and packageVersion should be obvious
  • cppHeaders, cppPackageProviders, csNamespaces, csPackageProviders should be that same as the above (though they should allow empty arrays)
  • Need to add nugetPackageLang to help make sure we can specify ConsumeCSharpModules correctly for C++ apps
• Config should verify that all fields are present if there are any nugetPackage objects in the react-native.config.js
• Dependency config tests should be added which verify that specifying these items (correctly and incorrectly) creates the correct config output

Motivation

We want to support community modules that are distributed as nuget packages, so we need to know how to handle them in RNW apps

Basic Example

No response

Open Questions

No response

[jonthysell]

Related task to update documentation: microsoft/react-native-windows-samples#645

[jonthysell]

Part of #7227