Repatriate the ASP.NET Core SDK under the monorepo

[Tyrrrz]

As far as I know, the ASP.NET Core SDK was split out from the previous monorepo, which included Passwordless.Server. While it makes sense for the Server repo to be separate from the SDK projects, keeping the SDKs together provides us with a lot of benefits:

• We can use the same exact CI workflow without any additions or changes
• Test and deploy flows will work exactly the same for both
• Dependent SDKs (.AspNetCore in this case) will always be tested and released against the latest version of the core SDK
• Better discoverability and issue management: users won't have to figure out where to report their bugs
• We can share tooling (.editorconfig etc) instead of copy-pasting

[Tyrrrz]

Note that the current GitHub token provided by the CI does not have permissions to push Passwordless.AspNetCore to the registry. The same problem will likely occur with the NuGet token too, I'm not sure what scopes are set there.

[abergs]

I even thought that maybe... maybe... we should add our examples into the same repo as the SDK. Unless there is a better way. Not sure yet!

[justindbaur]

add our examples into the same repo

Yes please, just have an examples directory.

[Tyrrrz]

@abergs you mean this repo, right?

https://github.com/passwordless/passwordless-dotnet-example

[Tyrrrz]

Added the example @abergs @justindbaur

It references the SDK by PackageReference, not ProjectReference, like Anders suggested, so that users can still easily copy-paste the sources.

Note the failing deploy job, something needs to be done about that