Build: Adding NuGet-Packages for Manager and Tools

[Countryen]

Version of SharpShell used: Any

Related type(s) of SharpShell-Server: Any

As previously discussed here: https://github.com/dwmkerr/sharpshell/issues/269#issuecomment-525995963

Demand for other Packages (besides SharpShell Package) rises. Important: The Packages need to be in sync, because currently, the Tools (e.G. Server Manager) need to be built with exactly the same version as SharpShell used in the project.

Also I reccomend making it obvious for consumer, that these additional packages are optionally, dev/IDE-related and not mandatory.

Part of the task to get this automated (CI/CD).

As also stated in the referenced issue, later it's possible that this is replaced/complemented by something like chocolatey.