This should unblock the consumption of the latest .NET Core SDK, which includes breaking changes in MSBuild. We don't _really_ need the MSBuild APIs which were broken because ProdCon v1 is dead. This removes the unused ProdCon v1 tasks and targets.
* Add build definition for Azure DevOps
* Put code for metapackages in a subfolder
* Update targets to prepare for submodules merging into this repo
* Add source code for windows installer
* Add source code for Debian installers