Add support for central package version management

[pombredanne]

See https://learn.microsoft.com/en-us/nuget/consume-packages/central-package-management
This is a recent feature whereby the package references versions are managed centrally rather than in each project file.

[wkl3nk]

@pombredanne There is a PR that adds support for Central Package Management. Would you like to give this PR a review, or can you forward it to another contributor that could review it? Thanks in advance.