Part of #4246
Changes:
* Update source code layout to follow the new conventions for this repo
* Update project files to use `<Reference>`
* Update targets to build NPM packages
* Update BuildTools to support custom 'restore' and 'test' targets
This changes DataProtection to build as projects instead of a pseudo-submodule. It replaces Package and ProjectReference with <Reference> items which custom targets then resolve.
* Pair implementations and unit tests side by side in src/ and test/ folders
* Update .sln and project paths
* Rename unit test projects from Test.csproj => Tests.csproj
* Update KoreBuild properties to allow building projects, not solutions
* 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
Changes:
* Add a test project with simple unit tests for the shared framework
* Add root-level Directory.Build.props/targets files
* Cleanup .csproj files to reduce duplication
Justin Kotalik
Nate McMaster
Ajay Bhargav Baaskaran
Nate McMaster