Adding Packages Api

[JonruAlveus]

fixes #2360

[timrogers]

Thanks for taking the time to add this ❤️ I've reviewed commit-by-commit and it looks good to me from an API and basic implementation perspective, but I'm not a .NET expert, so let's wait for @nickfloyd to return from holiday before we merge (if that's okay!).

[nickfloyd]

Yeah this all looks fantastic @JonruAlveus - other than the typos, this looks g2g! ❤️

[nickfloyd]

So this is one of those weird API domains where package versions are a subset of packages, yet a package version is a package.

What you've done here feels like it works - I'm glad you approached the relationship this way to help reduce namespace confusion - I think leaving PackageVersions out of this interface would've made things a bit more clumsy.

github.Packages.PackageVersions.GetAllForUser
github.Packages.GetAllForOrg

feels more elegant than something like (though possible):

github.PackageVersions.GetAllForUser
github.Packages.GetAllForOrg

While, as you've implemented, it can lead to a bit more verbose API call, I think the expression feels more natural ❤️ solid work here!

[JonruAlveus]

Thanks! It is a little odd. I took my inspiration from the GitHub Api docs where it's all grouped together in one Packages section.

I've just pushed a final fix for the typos also.

[nickfloyd]

release_notes: Added Packages and Package versions APIs