installing packages from NuGet server is slow

[Be-ing]

Installing vcpkg packages from a NuGet server is slow. This can take over 5 minutes with large dependencies like Qt. Setting up vcpkg on a small project, this is the longest step of the CI jobs!

During the CMake configure step, vcpkg hangs for a while at Attempting to fetch # packages from nuget.. I would not be surprised if some users wonder if vcpkg freezes at this time. User feedback about what is happening at this time would be nice.

How could vcpkg install be faster? I suspect the biggest speedup could come from splitting the release and debug builds in the binary cache and only installing whichever one is required for the current build. I suspect this could take substantial changes to vcpkg to work though.

NuGet uses ZIP for its packages. Using zstd compression instead could help. I think this would require changes upstream in NuGet. I think another archive format like tar would also be needed as well because I don't think ZIP can use zstd.