Package Improvements

[JasonBock]

There's a number of articles I've found recently that I should use to review my Spackle package setup and see if I can improve anything:

• https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/overview
• https://www.meziantou.net/ensuring-best-practices-for-nuget-packages.htm
• https://learn.microsoft.com/en-us/nuget/create-packages/package-authoring-best-practices?WT.mc_id=DT-MVP-5003978

Also, want to add central package management, among other various solution/project improvements.