Update internal SBRP targeting pack tooling to generate projects with correct casing

[ViktorHofer]

See discussion in dotnet/source-build-reference-packages#1189

The internal tool that generates the targeting packs for SBRP should get updated to emit project files in the correct casing (equal to the package id).

[MichaelSimons]

I implemented a low cost solution in https://dev.azure.com/dnceng/internal/_git/dotnet-source-build-utilities/pullrequest/49394. The long term direction is dotnet/source-build-reference-packages#1313.